Indian Patents
Title of Invention

"1-[6,7-SUBSTITUTED ALKOXYQUINOXALINYL) AMINOCARBONYL]-4-(HETERO) ARYLPIPERAZINE DERIVATIVES"
Abstract The present invention relates to novel quinoxaline-piperazine compounds represented by the general formula (1), l-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives and their pharmaceutically acceptable salts, a process for their preparation thereof, and compositions containing such compounds. Therapeutic methods for the treatment of hyperproliferative disorders, including cancers, by administering quinoxalin-piperazine compounds are also included.
Full Text l-[(6,7-SUBSTITUTEDALKOXYQUINOXALINYL)AMINOCARBONYL]-4-(HETERO)ARYLPIPERAZINE DERIVATIVES
FIELD OF THE INVENTION
The present invention relates to novel quinoxaline-piperazine compounds, l-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives and pharmaceutically acceptable salt thereof, process for the preparation thereof, and therapeutic methods for the treatment of hyperproliferative disorders, including cancers, by administering quinoxaline-piperazine compounds.
BACKGROUND OF THE INVENTION
Chemotherapeutics kill tumor cells by interfering with various stages of the cell division process. There are a number of classes of chemotherapeutics including alkylating agents (e.g., cyclophosphamide, carmustine, cisplatin), antimetabolites (e.g., methotrexate, 5-FU, gemcitabine), cytotoxic antibiotics (e.g., doxorubicin, mitomycin) and plant derivatives (e.g., paclitaxel, vincristine, etoposide). Chemotherapy is used as a primary treatment for leukemias, other blood cancers, and inoperable or metastatic solid cancers.
However, current chemotherapeutic agents have a few problems, including limited efficacy, debilitating adverse side effects and development of multidrug resistance.
Novel piperazine compounds may provide potent new therapeutic molecules for the treatment of disorders such as tumors. In association with new development of an anti-tumor agent, U. S. Patent Application Publication No. 2003/0092910 presents the piperazine compounds having formula (A)
(Figure Removed)
In U. S. Patent Application Publication No. 2003/0092910, the preparation of l-[(2-alkoxyquinoxalin-3-yl)aminocarbonyl-4-arylpiperazine is presented wherein Ra and Rb are fused to form C3-C4 unsaturated ring. But the compounds of formula A have only hydrogen atom at C-5, C-6, C-7 and C-8 position of quinoxaline ring.
Namely, the compounds listed in U. S. Patent Application Publication No. 2003/0092910 has no other group except hydrogen at C-6 of quinoxaline ring of l-[(2-alkoxyquinoxalin-3-yl)aminocarbonyl-4-arylpiperazine and the compounds with other groups except hydrogen at C-6 of quinoxaline have not been prepared and tested as an antitumor agent.

The present invention has studied l-[(2-alkoxyquinoxalin-3-yl)aminocarbonyl-4-arylpiperazine derivatives because of its prominent antitumor activities with very low toxicities and presents novel l-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives with other functional groups except hydrogen at C-6 of quinoxaline ring of l-[(2-alkoxyquinoxalin-3-yl)aminocarbonyl-4-arylpiperazine derivatives, the process of preparation and strong antitumor activities of these new compounds.
Accordingly, one object of the present invention is to provide the novel compounds, 1 -[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives.
Another object of the present invention is to provide a process for the preparation of the novel compounds, 1 -[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives.
A further object of the present invention is to use 1-[(6,7-substituted alkoxyquinoxalin-yl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives as antitumor agent.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises a novel quinoxalin-piperazine derivative of the general formula (1) or its pharmaceutically acceptable salt, process for the preparation thereof and their use in the treatment of a hyperproliferative disorder, disease or condition in a subject (e.g., a human patient or other animal subject). Methods according to the invention comprise administering to a subject an effective amount of a quinoxalin-piperazine compound according to the invention. Such a treatment can, e.g., prevent, ameliorate, and/or inhibit symptoms of the hyperproliferative condition, and/or can prevent or inhibit cellular proliferation or growth, for instance in a tumor, such as a malignant neoplasm. A treatment strategy of the invention would decrease the tumor burden, at least to a measurable degree, and improve survival of patients suffering from the hyperproliferative condition. Among the diseases, disorders and conditions susceptible to treatment by agents of the invention are neoplasms, and more specifically tumors of various origins (lung, colon, stomach, smooth muscle, esophagus, non-Hodgkin's lymphoma, non-small cell lung cancer, etc.).
Compounds Useful In Methods According To The Inventnion
Compounds useful in methods of the invention include quinoxaline-piperazine derivatives having formula (1), 1-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives:

(Figure Removed)
wherein X and Y are independently N or C-R7; R1 and R2 are independently hydrogen, C1-C6 alkoxy, CC1-C6
alkyl or halogen; R3 is C1-C6 alkyl; R4, R5, R6 andR7 are independently hydrogen, C1-C6 alkoxy, C1-C6 alkyl,
C1-C6 haloalkyl,C1-C6 alkylcarbonyl, halogen, cyano or nitro.
In the above definitions, the designation "halogen" represents F, Cl, Br or I.
The designation "alkoxy" represents C1-C6alkoxy containing methoxy, ethoxy, propoxy, isopropoxy,
butoxy, isobutoxy and t-butoxy.
The designation "alkyl" represents C1-C6 alkyl containing methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,
tbutyl, n-pentyl, isopentyl, n-hexyl, isohexyl and cyclohexyl.
The designation "haloalkyl" represnets C1-C6 alkyl, for example trifluoromethyl, in which hydrogen was
exchanged with halogen such as F or Cl.
The designation "alkylcarbonyl" represents carbonyl ketonized with alkyl such as methylcarbonyl or
ethylcarbonyl.
It is preferably understood that, in the structure of formula (1), X and Y are independently N, C-H, C-F, C-C1, C-CN, C-CH3, or C-OCH3, R1 and R2 are hydrogen, F, Cl, methyl or methoxy, R3 is methyl, R4, R5, and R6 are independently hydrogen, Cl, Br, nitro, methyl, trifluoromethyl, methoxy or acetyl and R7 is hydrogen, F, Cl, cyano, methyl or methoxy.
This invention also presents a process for the preparation of the compounds of general formula (1). The preparation method of formula (1) comprises a two-step procedure as shown in the following scheme 1. Scheme 1 comprises reacting a compound of the general formula (2), 6,7-substituted-2-alkoxy-3-aminoquinoxaline, with an L-C(=O)-L' group-providing agent in a conventional organic solvent in the presence of a base to obtain a compound of the general formula (3) and successively reacting the compound of the general formula (3) with a compound of the general formula (4), 1 -(hetero)arylpiperazine derivatives, in a conventional organic solvent in the presence of a base to give the compound of the general formula (1)
[Scheme 1]






wenein X, Y, R1, R2, R3, R4, R5 and R6 are the same as defined above, and L and L' are independently imidazole, Cl, ethoxy, phenoxy or 4-nitrophenoxy.
The two-step reaction in scheme 1 may be carried out successively without purification of the compound of the general formula (3) which is an intermediate produced in the above process.
The process for the preparation of the compounds of general formula (1) in scheme 1 may be explained in detail as follows:
The L-C(=O)-L' group-providing agent used in the above reaction may include 1,1-carbonyldiimidazole, phosgene, carbonyldiphenoxide, phenylchloroformate, 4-nitro phenylchloroformate and ethylchloroformate, and it may be used in an amount of 1.0-1.5 equivalents, preferably 1.0-1.1 equivalents with reference to the starting compound.
The reaction may be carried out in a conventional organic solvent such as, for example, tetrahydrofuran (THF), dichloromethane, acetonitrile, chloroform and dimethylformamide.
And also the reaction is preferably carried out in the presence of a coupling agent such as a conventional inorganic or organic base. Such conventional inorganic or organic bases used in the reaction may include sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, pyridine and l,8-diazabicyclo[5.4.0]undec-7-ene (hereinafter DBU).
The reaction may be carried out at a temperature between 0 °C and boiling point of the solvent used, preferably at room temperature to 100 °C and for 5-48 hours, preferably for 10-24 hours.
The second step in scheme 1, reaction of the compound (3) with the compound (4) to give the compound (1) may be carried out in the presence of a conventional organic solvent at the temperature of 50-100 °C for 5-48 hours. The compound (4) may be used by 1.0-1.5 equivalent.
And also the reaction is preferably carried out in the presence of a conventional inorganic or organic base, such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, pyridine, DBU or the like.
The isolation and purification of the compounds (2), (3) and (1) in Scheme 1 were performed with multi column chromatography (Quad3+; Biotage Co., VA, USA) and high-speed liquid column chromatography with auto sampler and structure of the compounds of the general formula (1) was analysed and confirmed with NMR and Mass spectrum.
And also the compounds of the general formula (2) that are used as the starting material, 6,7-substituted-2-alkoxy-3-aminoquinoxaline, are novel compounds and may be prepared by the following scheme 2; reacting a compound of the general formula (5) with sodium alkoxide which is NaOR3 (R3 is C)-C6 alkyl) to give a compound of the general formula (2);
[Scheme 2]


(Figure Removed)
wherein R1, R2 and R3 are the same as defined in scheme 1.
The compound of the general formula (5) may be prepared by a known method described in, for example, J. Med. Chem., 1995, 38, 3720-3740 or Bull. Chem. Soc. Jpn., 1998, 71, 1125-1135.
The alkoxy reaction in scheme 2 may be carried out with sodium alkoxide in a conventional organic solvent such as THF and sodium alkoxide may be used in an amount of 1.0-10.0 equivalents, preferably 1.0-1.1 equivalents with reference to the starting compound, the compound of the general formula (5).
Also a compound of the general formula (2) may be prepared by the following scheme 3; reacting a compound of the general formula (6) with 2,4-dimethoxybenzylamine to give a compound of the general formula (7) and reacting the compound of the formula (7) with trifluoroacetic acid (TFA) to give a compound of the general formula (2);
[Scheme 3]
(Figure Removed)
wherein R1, R2 and R3 are the same as defined in scheme 1.
The compound of the general formula (6) may be prepared by a known method described in, for example,/ Med. Chem. 1990, 33, 2240-2254.
The reaction of the compound of the general formula (6) with 2,4-dimethoxybenzylamine in scheme 2 may be carried out in a conventional organic solvent such as dimethylsulfoxide to produce a compound of the general formula (7); and 2,4-dimethoxybenzylamine may be used in an amount of 1.0-5.0 equivalents, preferably 1.0-1.1 equivalents with reference to the compound of the general formula (6).
And then the reaction of the compound of the general formula (7) with trifluoroacetic acid may be carried out in a conventional organic solvent such as dichloromethane to give a compound of the general formula (2). Trifluoroacetic acid may be used in an amount of 0.5-1.5 equivalents, preferably 1.0 equivalent with reference to dichloromethane.
Compounds of the pesent invention can be very active against a wide range of hyperproliferatvie diseases, including tumors and used as an anti-tumor agent.

The compounds of the present invention can be also mixed with pharmaceutically acceptable versples by a known method to give pharmaceutical compositions and thus the pharmaceutical compositions can be used to prevent or treat various kinds of tumors of human beings or mammals.
Therefore, the present invention includes pharmaceutical compositions containing a compound of the general formula (1) or a pharmaceutically acceptable salt thereof as an active ingredient.
Pharmaceutically acceptable salts of compounds of the general formula (1) are pharmaceutically acceptable inorganic, organic acids, alkali metal and ammonium; for example, salts with inorganic acids such as hydrochloric acid, bromic acid, sulfuric acid, sodium hydrogensulfate, phosphoric acid, nitric acid, carbonic acid; salts with organic acids such as formic acid, acetic acid, propionic acid, oxalic acid, succinic acid, benzoic acid, citric acid, maleic acid, malonic acid, tartaric acid, gluconic acid, lactic acid, fumaric acid, lactobionic acid, salicylic acid, acetyl salicylic acid(aspirin); salts with amino acids such as glycine, alanine, valine, leucine, isoleucine, serine, cysteine, cystine, asparaginic acid, glutamic acid, lysine, arginine, tyrosine, proline; salts with sulfonic acids such as methane sulfonic acid, ethane sulfonic acid, benzene sulfonic acid, toluene sulfonic acid; an alkali metal salt, for example, a sodium or potassium salt; an alkali earth metal salt, for example, a calcium or magnesium salt; an ammonium salt; a salt with an organic base which affords a physiologically-acceptable, for example a salt with methylamine, dimethylamine, trimethylamine, piperidine, morpholine or tris-(2-hydroxyethyl)amine, or the like.
Futrhermore, the novel compounds of the general formula (1) and pharmaceutically acceptable salts thereof may be combined with a non-toxic pharmaceutically acceptable vehicle such as carrier, adjuvant, and expient and then the mixture may be administered orally or parenterally in the form of tablets, capsules, troches, solutions, suspensions to prevent or treat various kinds of tumors of human beings or mammals.
Vehicles which can be used in the preparation of pharmaceutical compositions containing the compound of the general formula (1) as the active ingredient may include a sweetening agent, a binding agent, a dissolving agent, aids for dissolution, a wetting agent, an emulsifying agent, an isotonic agent, an adsorbent, a degrading agent, an antioxidant, an antiseptics, a lubricating agent, a filler, perfume or the like; such as lactose, dextrose, sucrose, mannitol, sorbitol, cellulose, glycine, silica, talc, stearic acid, stearin, magnesium stearate, calcium stearate, magnesium aluminum silicate, starch, gelatine, tragacanth gum, glycine, silica, alginic acid, sodium alginate, methyl cellulose, sodium carboxy methyl cellulose, agar, water, ethanol, polyethylenglycol, polyvinyl pyrrolidone, sodium chloride, potassium chloride, orange essence, strawberry essence, vanilla aroma or the like.
Daily dosage of the compound of the general formula (1) may be varied depending on age, body weight, sex of a patient, type of administration, health condition, degree of disease, etc. and generally 0.01 mg to 5,000 mg per day for 70 kg adult may be administered one to several times according to a doctor's prescription or a pharmacist's indication.

EXAMPLES
The invention may be further clarified by reference to the following Examples, which serve to exemplify some of the preferred embodiments, and not to limit the invention in any way.
EXAMPLE 1
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine (Compound 1)
a) 3-Amino-6-fluoro-2-methoxyquinoxaline
To 3-amino-2-chloro-6-fluoroquinoxaline (550 mg, 2.78 mmol) dissolved in tetrahydrofuran (40 ml), 25 wt % sodium methoxide (6.01 g, 27.8 mmol) in methanol was added at room temperature and stirred further at room temperature for 1 hour. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with dichloromethane and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (2:1) mixture and concentration gave 491 mg of the titled compound (yield, 91 %).
b) Ethyl 7V-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate
3-Amino-6-fluoro-2-methoxyquinoxaline (580 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added . The mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (3:1) mixture and concentration gave 740 mg of the titled compound (yield, 93 %).
c) l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl 7V-(6-fiuoro-2-methoxyquinoxalin-3-yl)carbamate (27 mg, 0.10 mmol) and 1 -phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiOa column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (2:1) mixture and concentration gave 34 mg of the titled compound (yield, 88 %). 'H NMR (300 MHz, CDC13): 5 3.29(s, 4H), 3.77(s, 3H), 4.14(s, 4H), 6.89-6.97(m, 4H), 7.24-7.56(m, 5H), 7.62-7.71(m,
EXAMPLE 2
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 2)

Ethyl Af-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-methoxyphenyl)piperazine were reared by the same way with the example 1 to obtain the titled compound (yield, 84 %). 'H NMR (200 MHz, CDC13): 6 3.15(s, 4H), 3.79-3.87(m, 6H), 4.11(s, 4H), 6.86-7.02(m, 4H), 7.18-7.22(m, 1H), 7.39-7.50(m, 1H), 7.65-7.72(m, 1H).
EXAMPLE 3 1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 3)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 87 %). *H NMR (300 MHz, CDC13): 5 3.28(s, 4H), 3.80(s, 6H), 4.13(s, 4H), 6.45-6.58(m, 3H), 7.01(s, 1H), 7.17-7.23(m, 2H), 7.37-7.70(m, 2H).
EXAMPLE 4 1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 4)
Ethyl jV-(6-fluoro-2-methoxyqumoxalin-3-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 80 %). *H NMR (200 MHz, CDC13): 8 3.18(s, 4H), 3.79(s, 6H), 4.08-4.15(m, 4H), 6.85-6.98(m, 4H), 7.22-7.76(m, 4H).
EXAMPLE 5
l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 72 %). MS(ESI) m/z442(M+l).
EXAMPLE 6
l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
6)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and
1 -(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 76 %). !H NMR (200 MHz, CDC13): 8 3.22(s, 4H), 3.79-3. 85(m, 12H), 4.13(s, 4H), 6.19(s, 2H), 7.20-7.34(m, 1H), 7.35-7.36(m, 1H), 7.44(s, 1H), 7.67-7.70(m,
EXAMPLE 7
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 7)

Ethyl N(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-methylphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 73 %). *H NMR (200 MHz, CDC13): 6 2.35(s, 3H), 2.98-3.03(m, 4H), 3.73-3.78(m, 3H), 4.10-4.14(m, 4H), 7.02-7.17(m, 2H), 7.19-7.29(m, 2H), 7.36(s, 1H), 7.48-7.60(m, 1H), 7.67-7.74(m,
EXAMPLE 8
l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 8)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 90 %). *H NMR (200 MHz, CDC13): 8 2.33(s, 3H), 3.26-3.30(m, 4H), 3.74-3.78(m, 3H), 4.13(s, 4H), 6.75-6.78(m, 3H), 7.14-7.28(m, 2H), 7.36(s, 1H), 7.44-7.51(dd, .7=9.8 and 2.4 Hz, 1H), 7.67-7.74(m, 1H).
EXAMPLE 9
l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound 9)
Ethyl 7V-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 65 %). 'H NMR (300 MHz, CDC13): 5 2.26(s, 3H), 3.20(s, 4H), 3.71(s, 3H), 4.12-4.18(m, 4H), 6.99-7.01(m, 3H), 7.26-7.32(m, 2H), 7.53-7.81(m, 2H).
EXAMPLE 10
l-[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
10)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 79 %). *H NMR (300 MHz, CDC13): 5 2.29(s, 6H), 3.27(s, 4H), 3.88(s, 3H), 4.14(s, 4H), 6.59(s, 3H), 7.01-7.10(s, 1H), 7.24-7.36(m, 2H), 7.47-7.7 l(m, 2H).
EXAMPLE 11
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 11)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were
reacted by the same way with the example 1 to obtain the titled compound (yield, 80 %). 'H NMR (200

MHz, CDC13): 6 3.34(s, 4H), 3.79(s, 3H), 4.10(s, 4H), 7.07-7.24(m, 3H), 7.35-7.43(m, 3H), 7.71(m, 1H).
EXAMPLE 12
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 12)
Ethyl Af-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(2-fluorophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 91 %). 'H NMR (200 MHz, CDC13): 6 3.18(s, 4H), 3.78(s, 3H), 4.13(s, 4H), 6.93-7.10(m, 5H), 7.20-7.34(m, 1H), 7.46-7.60(m, IH), 7.67-7.74(m, 1H).
EXAMPLE 13 1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 13)
Ethyl Ar-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(4-fluorophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 85 %). 'H NMR (300 MHz, CDC13): 5 3.19(s, 4H), 3.77(s, 3H), 4.13(s, 4H), 6.88-7.02(m, 4H), 7.23-7.27(m, IH), 7.45-7.71(m, 311).
EXAMPLE 14 1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 14)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1-(2-chlorophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 87 %). 1H NMR (200 MHz, CDC13): 5 3.14(s, 4H), 3.79(s, 3H), 4.13(s, 4H), 6.97-7.05(m, 2H), 7.22-7.28(m, 2H), 7.33-7.40(m, 2H), 7.46-7.5l(d, J-l0.2 Hz, IH), 7.66-7.73(m, IH).
EXAMPLE 15
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 15)
Ethyl Af-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 70 %). *H NMR (200 MHz, CDC13): 5 3.30(s, 4H), 3.76(s, 3H), 4.13(s, 4H), 6.77-6.91(m, 3H), 7.15-7.33(m, 3H), 7.44-7.58(d, J=10.0 Hz, IH), 7.58-7.75(m, IH).
EXAMPLE 16 1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 16)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1-(4-chlorophenyl)piperazine were
reacted by the same way with the example 1 to obtain the titled compound (yield, 95 %). *H NMR (300

MHz, CDC13): 8 3.25(s, 4H), 3.78(s, 3H), 4.13(s, 4H), 6.86(d, .7=8.4 Hz, 2H), 7.22-7.26(m, 3H), 7.44(m, lH)7.70(m,
EXAMPLE 17
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 1 7)
Ethyl AL(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(2-cyanophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 85 %). *H NMR (200 MHz, CDC13): 5 3.31(s, 4H), 3.73-3.85(m, 3H), 4.06-4.16(m, 4H), 7.03-7.1 l(m, 3H), 7.20-7.34(m, 1H), 7.50-7.62(m, 3H), 7.67-7.74(m,
EXAMPLE 18
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 1 8)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(4-acetylphenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 90 %). 'H NMR (200 MHz, CDC13): 5 2.54(s, 3H), 3.42-3.48(m, 4H), 3.79(s, 3H), 4.14(s, 4H), 6.89(d, 7=9.0 Hz, 2H), 7.10-7.50(m, 3H), 7.69-7.80(m, 1H), 7.91 (d, J=7.8 Hz, 2H).
EXAMPLE 19
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 1 9)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-fluorophenyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 86 %). *H NMR (200 MHz, DMSO-d6): 5 3.18(s, 4H), 3.62(s, 3H), 3.99-4.01(m, 4H), 7.01-7.18(m, 4H), 7.53-7.57(m, 1H), 7.70-7.78(m, 1H), 8.06-8. ll(m, 2H).
EXAMPLE 20
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 20)
Ethyl N-(6-fluoro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-pyridyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 79 %). 'H NMR (200 MHz, CDC13): 5 3.71(s, 7H), 4.1 l(s, 4H), 6.66(d, J=9.0 Hz, 2H), 7.10(m, 1H), 7.22-7.25(m, 1H), 7.38-7.54(m, 311), 7.65-7.68(m, 1H), 8.19(d, J=3.8 Hz, 1H).
EXAMPLE 21
1 -[(6-Fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 21)

Ethyl 7V-(6-fiuoro-2-methoxyquinoxalin-3-yl)carbainate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 1 to obtain the titled compound (yield, 71 %). 'H NMR (200 MHz, CDC13): 5 3.68(s, 4H), 3.96(s, 3H), 4.12(s, 4H), 6.23(t, J=4.4 Hz, 1H), 7.02(s, 1H), 6.89-7.00(m, 1H), 7.36-7.43(m, 1H), 7.67(m, 1H), 8.32(d,J=4.4 Hz, 2H).
EXAMPLE 22
1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine (Compound 22)
a) 3-Amino-6-chloro-2-methoxyquinoxaline
To 3-amino-2,6-dichloroquinoxaline (1.30 g, 6.07 mmol) dissolved in tetrahydrofuran (60 ml), 25 wt % sodium methoxide (13.1 g, 60.7 mmol) in methanol was added at room temperature and stirred further at room temperature for 90 minutes. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with dichloromethane and the organic layer was washed with water and dried over MgSCU. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a »-hexane:ethyl acetate (2:1) mixture and concentration gave 1.22 g of the titled compound (yield, 96 %).
b) Ethyl AL(6-chloro-2-methoxyquinoxalin-3-yl)carbamate
3-Amino-6-chloro-2-methoxyquinoxaline (629 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (3:1) mixture and concentration gave 803 mg of the titled compound (yield, 95 %).
c) l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine
EthylN-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate (27 mg, 0.10 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 36 mg of the titled compound (yield, 91 %). 'H NMR (300 MHz, CDC13): 8 3.22-3.30(m, 4H), 3.75-3.78(m, 3H), 4.08-4.13(m, 4H), 6.89-6.96(m, 3H), 7.19-7.44(m, 5H), 7.64-7.80(m, 1H).
EXAMPLE 23

1 [(R-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 23)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(2-methoxyphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 77 %). *H NMR (300 MHz, CDC13): 5 3.10-3.17(m, 4H), 3.80-3.89(m, 6H), 4.08-4.15(m, 4H), 6.88-7.07(m, 4H), 7.20-7.32(m, 1H), 7.41-7.44(m, 1H), 7.50-7.68(m, 1H), 7.82(s, 1H).
EXAMPLE 24
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 24)
Ethyl Ar-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 70 %). *H NMR (300 MHz, CDC13): 5 3.22-3.30(m, 4H), 3.76-3.80(m, 6H), 4.08-4.14(m, 4H), 6.46-6.57(m, 3H), 7.20(t, J=8.1 Hz, 1H), 7.34-7.44(m, 1H), 7.50-7.67(m, 1H), 7.80(s, 1H).
EXAMPLE 25
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 25)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 81 %). !H NMR (200 MHz, CDC13): 6 3.16(s, 4H), 3.78(s, 3H), 4.16(s, 4H), 6.88-6.93(m, 4H), 7.27-7.80(m, 4H).
EXAMPLE 26
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine
(Compound 26)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 81 %). MS(ESI) m/z458(M+l).
EXAMPLE 27
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine
(Compound 27)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and
l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 22 to obtain the

titled compound (yield, 84 %). !H NMR (300 MHz, CDC13): 6 3.17-3.25(m, 4H), 3.81-3.86(m, 12H), 4.09l4.16(m, 4H), 6.21(s, 2H), 7.21-7.30(m, 1H), 7.33-7.54(m, 1H), 7.58-7.69(m, 1H), 7.81(s,
EXAMPLE 28
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 28)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(2-methylphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 80 %). *H NMR (300 MHz, CDC13): 5 2.35(s, 3H), 2.95-3.02(m, 4H), 3.74-3.77(m, 3H), 4.08-4.14(m, 4H), 7.01-7 57(m, 7H), 7.64-7.85(m, 1H).
EXAMPLE 29 l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 29)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 90 %). *H NMR (300 MHz, CDC13): 5 3.20-3.30(m, 4H), 3.74-3.77(m, 3H), 4.11-4.14(m, 4H), 6.74-6.77(m, 3H), 7.16-7.25(m, 411), 7.64-7.8 l(m, 1H).
EXAMPLE 30
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound
30)
Ethyl Af-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 67 %). H NMR (300 MHz, CDC13): 6 2.33-2.40(m, 6H), 3.14-3.22(m, 4H), 3.69-3.76(m, 3H), 4.06-4.18(m, 4H), 6.97-7.04(m, 3H), 7.20-7.85(m, 4H).
EXAMPLE 31
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
31)
EthylN-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 79 %). *H NMR (300 MHz, CDC13): 6 2.29(s, 6H), 3.19-3.29(m, 4H), 3.73-3. 89(m, 3H), 4.11-4.14(m, 4H), 6.58(s, 3H), 7.19-7.25(m, 1H), 7.36-7.64(m, 2H), 7.67-7.81(m,
EXAMPLE 32

l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 32)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 84 %). 1H NMR (300 MHz, CDC13): 5 3.27-3.37(m, 4H), 3.76-3. 80(m, 3H), 4.12-4.14(m, 4H), 7.08-7.26(m, 4H), 7.36-7.45(m, 3H), 7.64-7.80(m, 1H).
EXAMPLE 33 l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 33)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-fluorophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 80 %). 'H NMR (300 MHz, CDC13): 5 3.12-3.21(m, 4H), 3.77-3. 84(m, 3H), 4.11-4.15(m, 4H), 6.95-7.10(m, 4H), 7.20-7.45(m, 3H), 7.65-7.82(m, 1H).
EXAMPLE 34 1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 34)
Ethyl 7V-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(4-fluorophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 77 %). *H NMR (300 MHz, CDC13): 5 3.13-3.20(m, 4H), 3.77(s, 3H), 4.14(s, 4H), 6.88-7.02(m, 4H), 7.20-7.24(m, 1H), 7.36-7.44(m, 1H), 7.50-7.67(m, 1H), 7.80(s,
EXAMPLE 35
1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 35)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(2-chlorophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 76 %). 'H NMR (300 MHz, CDC13): 5 3.08-3.17(m, 4H), 3.78-3.86(m, 3H), 4.09-4. 15(m, 4H), 7.00-7.07(m, 2H), 7.20-7.45(m, 5H), 7.65-7.84(m, 1H).
EXAMPLE 36 1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 36)
Ethyl Ar-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 85 %). *H NMR (300 MHz, CDC13): 5 3.22-3.32(m, 4H), 3.73-3.77(m, 3H), 4.11-4.14(m, 4H), 6.78-6.90(m, 3H), 7.19-7.44(m, 4H), 7.64-7.80(m, 1H).

EXAMPLE 37
1 -[(16-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 37)
Ethyl N(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(4-chlorophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 96 %). 'H NMR (300 MHz, CDC13): 6 3.18-3.26(m, 4H), 3.76(s, 3H), 4.11-4.14(m, 4H), 6.84-6.87(d, .7=8.7 Hz, 2H), 7.22-7.34(m, 3H), 7.41-7.53(m, 1H), 7.65-7.66(m, 1H), 7.79(s,
EXAMPLE 38
1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 38)
Ethyl Ar-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-cyanophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 91 %). :H NMR (300 MHz, CDC13): 5 3.25-3.32(m, 4H), 3.84(s, 3H), 4.08-4.15(m, 4H), 7.06-7.08(m, 2H), 7.21(m, 1H), 7.41-7.67(m,4H), 7.82(s,
EXAMPLE 39
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 39)
Ethyl N-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and l-(4-acetylphenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 85 %). !H NMR (300 MHz, CDC13): 6 2.54(s, 3H), 3.50(s, 4H), 3.80(s, 3H), 4.14(s, 4H), 6.89(d, J=7.7 Hz, 2H), 7.44(s, 1H), 7.66(s, 1H), 7.79(s, 1H), 7.79(s, 1H), 7.91(d, J=7.7 Hz, 2H).
EXAMPLE 40
l-[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 40)
Ethyl N(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(4-nitrophenyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 82 %). 'H NMR (300 MHz, DMSO-d4): 5 3.62-3.66(m, 8H), 4.06(s, 3H), 7.07(d, 7=9.0 Hz, 2H), 7.58(d, .7=8.4 Hz, 1H), 7.76-7.80(m,2H), 8.11 (d, .7=9.0 Hz, 2H),9.46(s,lH).
EXAMPLE 41 1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 41)
Ethyl Ar-(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1 -(2-pyridyl)piperazine were reacted
by the same way with the example 22 to obtain the titled compound (yield, 70 %). *H NMR (300 MHz,

CDC13): 5 3.63-3.73(m, 7H), 4.08-4.15(m, 4H), 6.68(d, J=8.7 Hz, 2H), 7.20-7.3l(m, 1H), 7.42-7.53(m, 2H)7.65-7.80(m, 2H), 8.21(d, J=3.6 Hz, 1H).
EXAMPLE 42
1 -[(6-Chloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 42)
Ethyl AL(6-chloro-2-methoxyquinoxalin-3-yl)carbamate and 1-(2-pyrimidyl)piperazine were reacted by the same way with the example 22 to obtain the titled compound (yield, 90 %). !H NMR (300 MHz, CDC13): 6 3.71(s, 4H), 3.99(s, 3H), 4.15(s, 4H), 6.55(s, 1H), 7.27-7.43(m, 2H), 7.66(s, 1H), 7.80(s, 1H), 8.35(s, 2H).
EXAMPLE 43 1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine (Compound 43)
a) 3-Amino-2-methoxy-6-methylquinoxaline
To 3-amino-2-chloro-6-methylquinoxaline (550 mg, 2.84 mmol) dissolved in tetrahydrofuran (30 ml), 25 wt % sodium methoxide (6.14 g, 28.4 mmol) in methanol was added at room temperature and stirred further at room temperature for 60 minutes. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with dichloromethane and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with «-hexane:ethyl acetate (2:1) mixture and concentration gave 467 mg of the titled compound (yield, 87 %).
b) Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate
3-Amino-2-methoxy-6-methylquinoxaline (568 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with n-hexane:ethyl acetate (3:1) mixture and concentration gave 768 mg of the titled compound (yield, 98 %).
c) l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate (26 mg, 0.10 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column
chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration

gave 34 mg of the titled compound (yield, 90 %). 'H NMR (300 MHz, CDC13): 5 2.42-2.48(m, 3H), 3.2)3.30(m, 4H), 3.77(s, 3H), 4.12(s, 4H), 6.90-7.12(m, 4H), 7.25-7.32(m, 3H), 7.48-7.65(m, 2H).
EXAMPLE 44
l-|(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 44)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1 -(2-methoxyphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 66 %). 1H NMR (300 MHz, CDC13): 5 2.42-2.49(m, 3H), 3.10-3.16(m, 4H), 3.80-3.89(m, 6H), 4.08-4.17(m, 4H), 6.88-7.1 l(m, 5H), 7.26-7.32(m, 1H), 7.48-7.64(m, 2H).
EXAMPLE 45
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 45)
Ethyl Af-(2-methoxy-6-rnethylquinoxalin-3-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 73 %). *H NMR (300 MHz, CDC13): 5 2.43-2.48(m, 3H), 3.23-3.30(m, 4H), 3.76-3. 87(m, 3H), 4.04-4.13(m, 4H), 6.45-6.50(m, 2H), 6.57(d, .7=8.4 Hz, 1H), 7.01-7.12(m, 1H), 7.17-7.33(m, 3H), 7.48-7.65(m, 2H).
EXAMPLE 46
l-|(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 46)
Ethyl 7V-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 80 %). 'H NMR (200 MHz, CDC13): 6 2.48(s, 3H), 3.16-3.14(m, 4H), 3.78-3.82(m, 6H), 4.13(s, 4H), 6.84-7.02(m, 4H), 7.14-7.33(m, 3H), 7.53-7.64(m,
EXAMPLE 47
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
47)
Ethyl N (2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 94 %). MS(ESI) m//438(M+l).
EXAMPLE 48

l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
48)
Ethyl Af-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and
l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 94 %). *H NMR (300 MHz, CDC13): 5 2.44-2.49(m, 3H), 3.18-3.25(m, 4H), 3.80-3.86(m, 12H), 4.04-4.13(m, 4H), 6.20(s, 2H), 7.02-7.20(m, IH), 7.31-7.40(m, IH), 7.46-7.63(m, 2H).
EXAMPLE 49
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-rnethylphenyl)piperazine (Compound 49)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1-(2-methylphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 95 %). *H NMR (300 MHz, CDC13): 5 2.32-2.56(m, 6H), 2.88-3.00(m, 4H), 3.77(s, 3H), 4.08-4.13(m, 4H), 7.02-7.04(m, 3H), 7.19-7.39(m, 3H), 7.51-7.65(m, 2H).
EXAMPLE 50
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 50)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 90 %). *H NMR (300 MHz, CDC13): 6 2.33-2.46(m, 6H), 3.14-3.37(m, 4H), 3.73-3.87(m, 3H), 4.05-4.18(m, 4H), 6.72-6.78(m, 3H), 7.00-7.20(m, 2H), 7.30-7.38(m, IH), 7.49-7.62(m, 2H).
EXAMPLE 51
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound
51)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 88 %). !H NMR (300 MHz, CDC13): 5 2.04-2.58(m, 9H), 3.14-3.20(m, 4H), 3.71-3.76(m, 3H), 4.07-4.14(m, 4H), 7.00-7.15(m, 4H), 7.25-7.76(m, 3H).
EXAMPLE 52
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
52)

Ethyl N(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(3,5-dimethylphenyl)piperazine werefcfeacted by the same way with the example 43 to obtain the titled compound (yield, 87 %). *H NMR (300 MHz, CDC13): 6 2.29(s, 6H), 2.42-2.48(m, 3H), 3.20-3.28(m, 4H), 3.75-3.80(m, 3H), 4.10-4.13(m, 4H), 6.59(s, 3H), 7.00-7.12(m, 1H), 7.31(d, J=8.4 Hz, 1H), 7.48-7.65(m, 2H).
EXAMPLE 53
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 53)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 82 %). 'H NMR (300 MHz, CDC13): 6 2.46-2.49(m, 3H), 3.18-3.31(m, 4H), 3.73-3. 80(m, 3H), 4.10-4.19(m, 4H), 7.10-7.20(m, 4H), 7.34-7.39(m, 2H), 7.56-7.65(m, 2H).
EXAMPLE 54 1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 54)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(2-fluorophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 79 %). *H NMR (300 MHz, CDC13): 5 2.42-2.49(m, 3H), 3.12-3.19(m, 4H), 3.79(s, 3H), 4.11-4.13(m, 4H), 6.97-7.12(m, 5H), 7.26-7.33(m, 1H), 7.48-7.63(m, 2H).
EXAMPLE 55 l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 55)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1 -(4-fluorophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 70 %). !H NMR (300 MHz, CDC13): 8 2.43-2.49(m, 3H), 3.13-3.21(m, 4 H), 3.77(s, 3H), 4.11-4.13(m, 4H), 6.88-6.99(m, 4H), 7.13(m, 1H), 7.25(m, 1H), 7.48-7.65(m, 2H).
EXAMPLE 56
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 56)
EthylN-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(2-chlorophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 66 %). 'H NMR (300 MHz, CDC13): 5 2.43-2.49(m, 3H), 3.10-3.15(m, 4H), 3.81(s, 3H), 3.08-4.12(m, 4H), 7.00-7. 12(m, 3H), 7.24-7.40(m, 3H), 7.49-7.65(m, 2H).
EXAMPLE 57

1 -[|E-Methoxy-6-methylquinoxalin-3-yl)aniinocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 57)
Ethyl N(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 72 %). 'H NMR (300 MHz, CDC13): 6 2.45(s, 3H), 3.26(s, 4H), 3.77(s, 3H), 4.08-4.18(m, 4H), 6.78-6.90(m, 3H), 7.15-7.38(m, 311), 7.56-7.64(m, 2H).
EXAMPLE 58 l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 58)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and l-(4-chlorophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 78 %). 'H NMR (300 MHz, CDC13): 5 2.44-2.47(m, 3H), 3.19-3.26(m, 4H), 3.78(s, 3H), 4.12(s, 4H), 6.87(d, .7=8.9 Hz, 2H), 7.01-7.1 l(m, 1H), 7.22-7.26(m, 3H), 7.52-7.61(m, 2H).
EXAMPLE 59
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 59)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1 -(2-cyanophenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 91 %). 'H NMR (300 MHz, CDC13): 5 2.46(s, 3H), 3.28(s, 4H), 3.86(s, 3H), 4.08-4.19(m, 4H), 7.01-7.08(m, 3H), 7.17-7.37(m, 1H), 7.49-7.61 (m,4H).
EXAMPLE 60
l-[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 60)
Ethyl Af-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1-(4-acetylphenyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 87 %). !H NMR (300 MHz, CDC13): 6 2.45-2.53(m, 6H), 3.47(s, 4H), 3.81(s, 3H), 3.87-4.13(m, 4H), 6.88(d, .7=8.7 Hz, 2H), 7.22-7.36(m, 2H), 7.56-7.76(m, 2H), 7.90(d, .7=8.7 Hz, 2H).
EXAMPLE 61
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 61)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1-(4-nitrophenyl)piperazine were
reacted by the same way with the example 43 to obtain the titled compound (yield, 86 %). *H NMR (300

MHz, CDC13): 5 2.46(s, 3H), 3.52-3.58(m, 4H), 3.82(s, 3H), 4.09-4.13(m, 4H), 6.85(d, J=9.2 Hz, 2H), .15(m, 1H), 7.41(m, 1H), 7.52-7.58(m, 2H), 8.16(d, J=9.2 Hz, 2H).
EXAMPLE 62
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 62)
Ethyl N-(2-methoxy-6-methylquinoxalin-3-yl)carbamate and 1-(2-pyridyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 83 %). 1H NMR (300 MHz, CDC13): 5 2.43-2.47(m, 3H), 3.63-3.73(m, 7H), 4.13(s, 4H), 6.67(d, J=8A Hz, 2H), 7.01-7.12(m, 1H), 7.30-7.33(m, 1H), 7.48-7.62(m, 3H), 8.21(dd,J=4.8 and 1.5 Hz, 1H).
EXAMPLE 63
1 -[(2-Methoxy-6-methylquinoxalin-3-yl)aminocarbonyl]-4-(2-pyrimidyll)piperazine (Compound 63)
Ethyl N(2-methoxy-6-methylquinoxalin-3-yl)carbarnate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 43 to obtain the titled compound (yield, 93 %). *H NMR (300 MHz, CDC13): 6 2.47(s, 4H), 3.71(s, 3H), 3.91-3.99(m, 4H), 4.13(s, 3H), 6.53(s, 1H), 7.01-7.13(m, 1H), 7.27-7.30(m, 1H), 7.52-7.61(m, 2H), 8.33(d, J=4.8 Hz, 2H).
EXAMPLE 64
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine (Compound 64)
a) 3-Amino-2,6-dimethoxyquinoxaline
To 3-amino-2-chloro-6-methoxyquinoxaline (1.50 g, 7.16 mmol) dissolved in tetrahydrofuran (60 ml), 25 wt % sodium methoxide (15.5 g, 71.6 mmol) in methanol was added at room temperature and stirred further at room temperature for 21 hours. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with dichloromethane and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 1.18 g of the titled compound (yield, 80 %).
b) Ethyl Ar-(2,6-dimethoxyquinoxalin-3-yl)carbamate
3-Amino-2,6-dimethoxyquinoxaline (616 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated
under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography.

Extraction of the residue with a «-hexane:ethyl acetate (3:1) mixture and concentration gave 799 mg of the titBlpcompound (yield, 96 %).
c) l-[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate (28 mg, 0.10 mmol) and 1 -phenylpiperazine (24 mg, 0. 1 5 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0. 1 5 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (2:1) mixture and concentration gave 36 mg of the titled compound (yield, 92 %). !H NMR (300 MHz, CDC13): 6 3.27(s, 4H), 3.73-3. 86(m, 6H), 4.08-4.1 l(m, 4H), 6.88-7.03(m, 4H), 7.15(s, 1H), 7.26-7.33(m, 3H), 7.57-7.62(m,
EXAMPLE 65
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 65)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and 1 -(2-methoxyphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 84 %). *H NMR (300 MHz, CDC13): 8 3.15(s, 4H), 3.83-3.89(m, 9H), 4.12-4.17(m, 4H), 6.88-6.95(m, 3H), 7.02-7.05(m, 1H), 7.14(d,J=8.7Hz, 1H), 7.31(s, 1H), 7.51 (d, .7=8.7 Hz, 1H), 7.63(d, .7=9.0 Hz, 1H).
EXAMPLE 66
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 66)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 80 %). *H NMR (300 MHz, CDC13): 5 3.28(s, 4H), 3.80-3.87(m, 9H), 4.1 l(s, 4H), 6.45-6.49(m, 2H), 6.56(d, J=8.4 Hz, 1H), 6.91(s, 1H), 7.04-7.36(m, 3H), 7.53-7.62(m,
EXAMPLE 67
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 67)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 81 %). *H NMR (200 MHz, CDC13): 5 3.16(s, 4H), 3.78-3. 88(m, 9H), 4.12-4.17(m, 4H), 6.84-6.97(m, 4H), 7.16-7.32(m, 3H), 7.62-7.66(m,

EXAMPLE 68
l%^,6-Diniethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound 68)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 81 %). MS(ESI) m/z
454 (MH).
EXAMPLE 69
l-[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound 69)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 97 %). 1H NMR (300 MHz, CDC13): 5 3.55-3.87(m, 10H),4.12(s,4H), 6.67(d, J=8.4Hz, 1H), 7.14(d, J=9.0Hz, lH),7.25(s, 1H), 7.34(s, 1H), 7.51(t, J=7.2 Hz, 1H), 7.64(d, J-9.0 Hz, 1H), 8.2 l(d, J=3.6 Hz, 1H).
EXAMPLE 70
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 70)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2-methylphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 5 2.35(s, 3H), 2.95-3.02(m, 4H), 3.75-3.90(m, 6H), 4.09-4.13(m, 4H), 6.99-7.31(m, 7H), 7.50-7.66(m,
EXAMPLE 71
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 71)
Ethyl jV-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 95 %). *H NMR (300 MHz, CDC13): 8 2.33(s, 3H), 3.26(s, 4H), 3.72-3. 89(m, 6H), 4.09-4. 18(m, 4H), 6.72-6.78(m, 4H), 7.03-7.37(m, 3H), 7.57-7.65(m,
EXAMPLE 72
l-[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound 72)
Ethyl Ar-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were
reacted by the same way with the example 64 to obtain the titled compound (yield, 87 %). !H NMR (300

MHz, CDC13): 8 2.33-2.36(m, 6H), 3.14-3.22(m, 4H), 3.70-3.90(m, 6H), 4.09-4. 15(m, 4H), 6.67-7.32(m, 6H)Jj7.50-7.65(m,
EXAMPLE 73
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound 73)
EthylN-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 65 %). *H NMR (300 MHz, CDC13): 6 2.28(s, 6H), 3.26(s, 4H), 3.76-3.87(m, 6H), 4.1 l(s, 4H), 6.59(s, 2H), 6.90(m, 1H), 7.14(d, J -8.7 Hz, 1H), 7.32(s, 1H), 7.51(d, J=7.5 Hz, 1H), 7.64(d, J=8.7 Hz, 1H).
EXAMPLE 74
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 74)
EthylN-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 77 %). 1H NMR (300 MHz, CDC13): 5 3.33(s, 4H), 3.74-3.90(m, 6H), 4.09-4. 19(m, 4H), 6.92(s, 1H), 7.02-7.19(m, 5H), 7.38(t, .7=7.5 Hz, 1H), 7.59-7.66(m, 1H).
EXAMPLE 75 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 75)
Ethyl A^-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2-fluorophenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 72 %). 1H NMR (300 MHz, CDC13): 5 3.18(s, 4H), 3.73-3. 88(m, 6H), 4.11-4.15(m, 4H), 6.88-7.1 5(m, 5H), 7.33(s, 1H), 7.51(d, J=8.7 Hz, 1H), 7.64(d, J=9.0 Hz, 1H).
EXAMPLE 76 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 76)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and 1 -(4-fluorophenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 5 3.17(s, 4H), 3.78-3. 89(m, 6H), 4.11-4.15(m, 4H), 6.88-7.02(m, 4H), 7.14-7.36(m, 3H), 7.58-7.62(m, 1H).
EXAMPLE 77 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 77)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and 1 -(2-chlorophenyl)piperazine were reacted

by the same way with the example 64 to obtain the titled compound (yield, 89 %). !H NMR (300 MHz, ): 6 3.09-3.16(m, 4H), 3.79-3.90(m, 6H), 4.10-4.16(m, 4H), 7.00-7.30(m, 7H), 7.38-7.66(m, 1H).
EXAMPLE 78
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 78)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 85 %). 'H NMR (300 MHz, CDC13): 5 3.21-3.32(m, 4H), 3.75-3.88(m, 6H), 4.10-4.13(m, 4H), 6.80-6.90(m, 4H), 7.14-7.29(m, 3H), 7.63-7.66(m, 1H).
EXAMPLE 79 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 79)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and 1-(4-chlorophenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 86 %). 1H NMR (300 MHz, CDC13): 5 3.25(s, 4H), 3.77(s, 3H), 3.87(s, 3H), 4.09-4.12(m, 4H), 6.86-7.00(m, 3H), 7.12-7.24(m, 3H), 7.55-7.65(m, 2H).
EXAMPLE 80 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 80)
Ethyl ./V-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2-cyanophenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 94 %). 'H NMR (200 MHz, CDC13): 8 3.30(s, 4H), 3.88-3.90(m, 6H), 4.07-4.20(m, 4H), 6.94-7.07(m, 3H), 7.27-7.34(m, 2H), 7.53-7.63(m, 3H).
EXAMPLE 81 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 81)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(4-acetylphenyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 87 %). 'H NMR (200 MHz, CDC13): 8 2.54-2.58(m, 3H), 3.49-3.67(m, 4H), 3.87-3.96(m, 6H), 4.12-4.16(m, 4H), 6.87-7.03(m, 2H), 7.19-7.31(m, 3H), 7.62-7.66(m, 1H), 7.89-7.97(m, 2H).
EXAMPLE 82 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 82)
Ethyl N-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(4-nitrophenyl)piperazine were reacted
by the same way with the example 64 to obtain the titled compound (yield, 81 %). 1H NMR (300 MHz,

CDC13): 5 3.57(s, 4H), 3.75-3.87(m, 6H), 4.09-4.16(m, 4H), 6.84(d, J=9.3 Hz, 2H), 6.91-7.27(m, 3H), 7.56)7.63(m, 1H), 8.16(d, J=9.3 Hz, 2H).
EXAMPLE 83 1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 83)
Ethyl N2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2-pyridyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 84 %).
'I-INMR (300 MHz, CDC13): 5 3.87(s, 3H), 3.73-3.88(m, 6H), 4.1 l-4.15(m, 4H), 6.88-7.15(m, 5H), 7.33(s, HI), 7.51(d, J=8.7 Hz, 1H), 7.64(d, J=9.0 Hz, 1H).
EXAMPLE 84
1 -[(2,6-Dimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 84)
Ethyl 7V-(2,6-dimethoxyquinoxalin-3-yl)carbamate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 64 to obtain the titled compound (yield, 80 %). 1H NMR (300 MHz, CDC13): 5 3.72(s, 3H), 3.87-3.96(m, 7H), 4.12-4.15(m, 4H), 6.54(t, .7=4.8 Hz, 1H), 6.92(s, 1H), 7.04-7.36(m, 3H), 7.62(m, 1H), 8.34(d, J=4.8 Hz, 2H).
EXAMPLE 85
1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine (Compound 85)
a) 2-(2,4-Dimethoxybenzylamino)-6-fluoro-3-methoxyquinoxaline
To 2-chloro-6-fluoro-3-methoxyquinoxaline (4.00 g, 18.8 mmol) dissolved in dimethylsulfoxide (40 ml), 2,4-dimethoxybenzylamine (7.86 g, 47.0 mmol) was added at room temperature. The mixture was stirred at room temperature for 24 hours and then water was added thereto. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSO4 After concentration under the reduced pressure, the crude product was purified by 8162 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (6:1) mixture and concentration gave 4.45 g of the titled compound (yield, 92 %).
b) 2-Amino-6-fluoro-3 -methoxyquinoxaline
To 2-(2,4-dimethoxybenzylamino)-6-fluoro-3-methoxyquinoxaline (2.70 g, 7.86 mmol), 60 ml of 50 % trifluoroacetic acid in dichloromethane was added at room temperature. The resulting mixture was stirred at room temperature for 24 hours and concentrated under the reduced pressure to remove the solvent. The residue was neutralized with saturated sodium bicarbonate solution and then NaCl solution was added
thereto. The product was extracted with dichloromethanee and the organic layer was dried over MgSO4.

After concentration under the reduced pressure, the crude product was purified by SiO2 column chrc|iiatography. Extraction of the residue with a n-hexane:ethyl acetate (4:1) mixture and concentration gave 1.27 g of the titled compound (yield, 84 %).
c) Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate
2-Amino-6-fluoro-3-methoxyquinoxaline (580 mg, 3.00 mmol) and ethyl chloroforrnate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (3:1) mixture and concentration gave 756 mg of the titled compound (yield, 95 %).
d) l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate (27 mg, 0.10 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (2:1) mixture and concentration gave 34 mg of the titled compound (yield, 83 %). 'H NMR (300 MHz, CDC13): 6 3.28-3.31(m, 4H), 3.75-3.78(m, 4H), 4.15(s, 4H), 6.90-6.97(m, 3H), 7.24-7.42(m, 5H), 7.80(dd, J=9.0 and 6.0 Hz, 1H).
EXAMPLE 86
l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 86)
Ethyl A^-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and 1-(2-methoxyphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 82 %). 1H NMR (200 MHz, CDC13): 5 3.14-3.17(m, 4H), 3.78-3.81(m, 4H), 3.88(s, 3H), 4.14(s, 3H), 6.88-7.41(m, 7H), 7.81(dd, J=9.0 and 5.7 Hz. 1H).
EXAMPLE 87 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 87)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 77 %). 1H NMR (300 MHz, CDC13): 6 3.28-3.31(m, 4H), 3.74-3.77(m, 4H), 3.80(s, 3H), 4.15(s, 3H), 6.46-6.58(m, 2H), 7.18-7.28(m, 4H), 7.40(dd, J=9.3 and 2.7 Hz, 1H), 7.78-7.81(m, 1H).

EXAMPLE 88
1^6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 88)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 84 %). *H NMR (200 MHz, CDC13): 5 3.15-3.18(m, 4H), 3.78(s, 4H), 4.15(s, 3H), 6.85-6.96(m, 4H), 7.22-7.42(m, 3H), 7.81(dd, J=9.0 and 6.0 Hz, 1H).
EXAMPLE 89 l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-diniethoxyphenyl)piperazine (Compound 89)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 76 %). MS(ESI)
m/z442(M+l).
EXAMPLE 90
l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
90)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and
l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 83 %).
EXAMPLE 91 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 91)
Ethyl Ar-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-methylphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 77 %). 'H NMR (200 MHz, CDC13): 5 2.95(s, 3H), 2.99-3.02(m, 4H), 3.74-3.77(m, 4H), 4.15(s, 3H), 7.01-7.05(m, 2H), 7.17-7.42(m, 5H), 7.81-7.84(m, 1H).
EXAMPLE 92 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 92)
Ethyl Ar-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 87 %). 1H NMR (200 MHz, CDC13): 5 2.33(s, 3H), 3.26-3.30(m, 4H), 3.74-3.77(m, 4H), 4.15(s, 3H), 6.74-6.77(m, 3H), 7.16-7.29(m, 3H), 7.40(dd, 3=9.6 and 2.7 Hz, 1H), 7.78-7.81(m, 1H).

EXAMPLE 93
l^f^-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound 93)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 76 %). *H NMR (300 MHz, CDC13): 5 2.36(s, 6H), 3.18-3.21(m, 4H), 3.69-3.72(m, 4H), 4.15(s, 3H), 6.97-7.04(m, 3H), 7.22-7.42(m, 4H), 7.82-7.87(m, 1H).
EXAMPLE 94 l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound 94)
Ethyl Ar-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 86 %). 'H NMR (300 MHz, CDC13): 8 2.29(s, 6H), 3.25-3.29(m, 4H), 3.73-3.77(m, 4H), 4.16(s, 3H), 6.55-6.59(m, 3H), 7.21-7.43(m, 3H), 7.78-7.83(m, 1H).
EXAMPLE 95 l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 95)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 85 %). 'H NMR (200 MHz, CDC13): 6 3.36(s, 4H), 3.78(s, 4H), 4.16(s, 3H), 7.08-7.41(m, 7H), 7.79(t, J=8.4 Hz, 1H).
EXAMPLE 96
1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 96)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-fluorophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 85 %). !H NMR (200 MHz, CDC13): 5 3.17-3.20(m, 4H), 3.77-3.80(m, 4H), 4.13(s, 3H), 6.97-7.09(m, 4H), 7.24-7.41(m, 3H), 7.81-7.82(m, 1H).
EXAMPLE 97 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 97)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and 1-(4-fluorophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 82 %). 1H NMR (300 MHz, CDC13): 5 3.18-3.21(m, 4H), 3.74-3.78(m, 4H), 4.14(s, 3H), 6.88-6.92(m, 4H), 7.25-7.42(m, 3H), 7.76-7.81(m, 1H).

EXAMPLE 98
l(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 98)
Ethyl N-fluoro-S-methoxyquinoxalin-2-yOcarbamate and 1-(2-chlorophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 87 %). !H NMR (200 MHz, CDC13): 6 3.13-3.16(m, 4H), 3.78-3.81(m, 4H), 4.15(s, 3H), 7.02-7.06(m, 3H), 7.23-7.42(m, 4H), 7.82-7.83(m, 1H).
EXAMPLE 99 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 99)
Ethyl Ar-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 82 %). *H NMR (200 MHz, CDC13): 8 3.30(s, 4H), 3.91(s, 4H), 4.15(s, 3H), 6.79-6.91(m, 3H), 7.17-7.42(m, 4H), 7.79(m, 1H).
EXAMPLE 100
1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 100)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and 1-(4-chlorophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 86 %). *H NMR (300 MHz, CDC13): 5 3.24-3.27(m, 4H), 3.74-3.77(m, 4H), 4.15(s, 3H), 6.84-6.89(m, 2H), 7.14-7.43(m, 5H), 7.77-7.82(m, 1H).
EXAMPLE 101 1 - [ (6-Fluoro-3 -methoxyquinoxalin-2-yl)aminocarbonyl] -4-(2-cyanophenyl)piperazine (Compound 101)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-cyanophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 88 %). 'H NMR (200 MHz, CDC13): 6 3.31(s, 4H), 3.84(s, 4H), 4.15(s, 3H), 7.03-7.10(m, 2H), 7.25-7.61(m, 5H), 7.82(dd, J=8.7 and 5.7 Hz, 1H).
EXAMPLE 102 l-[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 102)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and 1-(4-acetylphenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 91 %). !H NMR (200 MHz, CDC13): 5 2.54(s, 3H), 3.50(s, 4H), 3.90(s, 4H), 4.15(s, 3H), 6.89(d, 7=8.7 Hz, 2H), 7.25-7.62(m, 3H), 7.79(s, 1H), 7.9l(d, J=9.0 Hz, 1H).

EXAMPLE 103
]^(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 103)
Ethyl N-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(4-nitrophenyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 89 %). 1H NMR (200 MHz, DMSO-d6): 5 3.57-3.59(m, 4H), 3.64-3.66(m, 4H), 4.04(s, 3H), 7.05(d, 3=9.5 Hz, 2H), 7.44(dt, J=8.9 and 2.9 Hz, 1H), 7.54(dd, J=9.8 and 2.8 Hz, 1H), 7.81(dd, J=9.1 and 5.9 Hz, 1H), 8.08(d, J=9.4 Hz, 2H), 9.35(s, 1H).
EXAMPLE 104 1 -[(6-Fluoro-3 -methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 104)
Ethyl A/-(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-pyridyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 80 %). :H NMR (200 MHz, CDC13): 5 3.72-3.76(m, 8H), 4.16(s, 3H), 6.66-6.70(m, 2H), 7.24-7.52(m, 4H), 7.80-7.81(m, 1H), 8.21(dd, .7=5.4 and 1.8 Hz, 1H).
EXAMPLE 105 1 -[(6-Fluoro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 105)
Ethyl N(6-fluoro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 85 to obtain the titled compound (yield, 79 %). 'H NMR (200 MHz, CDC13): 5 3.69(s, 4H), 3.98(s, 4H), 4.14(s, 3H), 6.54(t, J=4.8 Hz, 1H), 7.21-7.41(m, 3H), 7.79(t, J=8.4 Hz, 1H), 8.34(d, J=4.8 Hz, 2H).
EXAMPLE 106 1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine (Compound 106)
a) 6-Chloro-2-(2,4-dimethoxybenzylamino)-3-methoxyquinoxaline
To 2,6-dichloro-3-methoxyquinoxaline (4.00 g, 17.5 mmol) dissolved in dimethylsulfoxide (40 ml), 2,4-dimethoxybenzylamine (14.6 g, 87.3 mmol) was added at room temperature. The mixture was stirred at room temperature for 36 hours and then water was added thereto. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (30:1) mixture and concentration gave 4.93 g of the titled compound (yield, 78 %).
b) 2-Amino-6-chloro-3-methoxyquinoxaline
To 6-chloro-2-(2,4-dimethoxybenzylamino)-3-methoxyquinoxaline (4.42 g, 12.3 mmol), 50 ml of

50 % trifluoroacetic acid in dichloromethane was added at room temperature. The resulting mixture was stirrqjj at room temperature for 18 hours and concentrated under the reduced pressure to remove the solvent. The residue was neutralized with saturated sodium bicarbonate solution and then NaCl solution was added thereto. The product was extracted with dichloromethanee and the organic layer was dried over MgSO,*. After concentration under the reduced pressure, the crude product was purified by SiC-2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (4:1) mixture and concentration gave 1.52 g of the titled compound (yield, 59 %).
c) Ethyl A^-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate
2-Amino-6-chloro-3-methoxyquinoxaline (629 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a «-hexane: ethyl acetate (3:1) mixture and concentration gave 811 mg of the titled compound (yield, 96 %).
d) l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl Af-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate (28 mg, 0.10 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiC>2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 36 mg of the titled compound (yield, 94 %). *H NMR (300 MHz, CDC13): 6 3.30(s, 4H), 3.77(s, 4H), 4.15(s, 3H), 6.90-6.97(m, 3H), 7.28-7.45(m, 4H), 7.75-7.76(m, 1H).
EXAMPLE 107
1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound
107)
Ethyl jV-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1-(2-methoxyphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 92 %). *H NMR (300 MHz, CDC13): 5 3.17(s, 4H), 3.82(s, 4H), 3.89(s, 3H), 4.15(s, 3H), 6.89-6.97(m, 3H), 7.06(m, 1H), 7.45(m, 1H), 7.75(s, 2H).
EXAMPLE 108
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound

108)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 85 %). 1H NMR (300 MHz, CDC13): 6 3.14-3.16(m, 4H), 3.76-3.80(m, 7H), 4.14(s, 3H), 6.46-6.58(m, 3H), 7.14-7.44(m, 3H), 7.62-7.74(m, 2H).
EXAMPLE 109
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound
109)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1-(4-methoxyphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 90 %). *H NMR (200 MHz, CDC13): 8 3.17(s, 4H), 3.78(s, 7H), 4.15(m, 3H), 6.85-6.96(m, 4H), 7.29-7.49(m, 2H), 7.74-7.77(m, 2H).
EXAMPLE 110
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-diniethoxyphenyl)piperazine (Compound
110)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 91 %). MS(ESI)m/z458(M+l).
EXAMPLE 111
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
111)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and
l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 83 %). !H NMR (300 MHz, CDC13): 6 3.24(s, 4H), 3.81-3.86(m, 12H), 4.15(s, 3H), 6.21(s, 2H), 7.36-7.45(m, 1H), 7.27(s, 1H), 7.36-7.45(m, 1H), 7.64-7.75(m, 2H).
EXAMPLE 112
1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 112)
Ethyl N(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-methylphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 89 %). *H NMR (300 MHz, CDC13): 5 2.35(s, 3H), 3.01(s, 4H), 3.76(s, 4H), 4.14(s, 3H), 7.03-7.52(m, 6H), 7.68-7.77(m, 2H).

EXAMPLE 113
Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 113)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 97 %). *H NMR (300 MHz, CDC13): 8 3.27-3.30(m, 4H), 3.74-3.77(m, 4H), 4.15(s, 3H), 6.75-6.78(m, 3H), 7.11-7.45(m, 3H), 7.74-7.76(m, 2H).
EXAMPLE 114
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound
114)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 8 2.36(s, 3H), 3.14(s, 4H), 3.70(s, 4H), 4.15(s, 3H), 6.95-7.01(m, 3H), 7.26-7.46(m,3H), 7.61-7.81(m,2H).
EXAMPLE 115
l-|(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
115)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 85 %). 'H NMR (300 MHz, CDC13): 8 2.29(s, 6H), 3.25-3.29(m, 4H), 3.73-3.76(m, 4H), 4.15(s, 3H), 6.59(s, 3H), 7.30-7.49(m, 3H), 7.74-7.77(m, 1H).
EXAMPLE 116 1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 116)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 81 %). H NMR (300 MHz, CDC13): 8 3.37-3.38(m, 4H), 3.77-3.80(m, 4H), 4.16(s, 3H), 7.08-7.45(m, 6H), 7.73-7.76(m, 2H).
EXAMPLE 117
1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 117)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1 -(2-fluorophenyl)piperazine were
reacted by the same way with the example 106 to obtain the titled compound (yield, 93 %). 1H NMR (300
MHz, CDC13): 8 3.18(s, 4H), 3.78(s, 4H), 4.14(s, 3H), 6.94-7.1 l(m, 4H), 7.35-7.45(m, 2H), 7.74-7.77(m,
2H).

EXAMPLE 118
l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 118)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1 -(4-fluorophenyl)piperazine were
reacted by the same way with the example 106 to obtain the titled compound (yield, 88 %). 'H NMR (300
MHz, CDC13): 5 3.19-3.22(m, 4H), 3.75-3.78(m, 4H), 4.16(s, 3H), 6.89-6.93(m, 4H), 7.29-7.46(m, 2H),
7.74-7.76(m, 1H).
EXAMPLE 119
1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 119)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(2-chlorophenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 91 %). *H NMR (300 MHz, CDC13): 6 3.15(s, 4H), 3.79(s, 4H), 4.15(s, 3H), 6.99-7.06(m, 2H), 7.23-7.45(m, 4H), 7.74-7.79(m, 2H).
EXAMPLE 120 l-[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 120)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 86 %). :H NMR (300 MHz, CDC13): 8 3.30(s, 4H), 3.76(s, 4H), 4.15(s, 3H), 6.79-6.90(m, 3H), 7.15-7.45(m, 3H), 7.62-7.75(m, 2H).
EXAMPLE 121 1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 121)
Ethyl AL(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(4-chlorophenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 94 %). 'H NMR (300 MHz, CDC13): 5 3.25(s, 4H), 3.76(s, 4H), 4.15(s, 3H), 6.86(d, J= 9.0 Hz, 2H), 7.22-7.45(m, 4H), 7.72-7.75(m, 2H).
EXAMPLE 122 1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 122)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1-(2-cyanophenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 89 %). 'H NMR (300 MHz, CDC13): '5 3.30(s, 4H), 3.84(s, 3H), 4.14(s, 3H), 7.02-7.10(m, 2H), 7.35-7.89(m, 6H).

EXAMPLE 123
1 -[^-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 123)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and l-(4-acetylphenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 81 %). *H NMR (300 MHz, CDC13): 6 2.54(s, 3H), 3.50(s, 4H), 3.79(s, 4H), 4.15(s, 3H), 6.89(d, J=9.0 Hz, 2H), 7.31-7.50(m, 2H), 7.65-7.75(m, 2H), 7.90(d, J=8.7 Hz, 2H).
EXAMPLE 124
1 -[ (6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 124)
Ethyl 7V-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1-(4-nitrophenyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 96 %). *H NMR (300 MHz, DMSO-J6): 6 3.57-3.65(m, 8H), 4.17(s, 3H), 7.05(d, J=9.5 Hz, 2H), 7.55(dd, J=8.9 and 2.2 Hz, 1H), 7.74-7.79(m, 2H), 8.08(d, J=9.4 Hz, 2H), 9.40(s, 1H).
EXAMPLE 125
1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 125)
Ethyl 7V-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1 -(2-pyridyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 87 %). 'H NMR (300 MHz, CDC13): 8 3.73(m, 8H), 4.15(s, 3H), 6.68(d, J=8.4 Hz, 2H), 7.11-7.76(m, 5H), 8.21(dd, J=3.6 and 0.6 Hz, 1H).
EXAMPLE 126 1 -[(6-Chloro-3-methoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 126)
Ethyl N-(6-chloro-3-methoxyquinoxalin-2-yl)carbamate and 1-(2-pyrimidyl)piperazine were reacted by the same way with the example 106 to obtain the titled compound (yield, 90 %). *H NMR (300 MHz, CDC13): 5 3.69-3.73(m, 4H), 3.98(s, 4H), 4.16(s, 3H), 6.54-6.55(m, 1H), 7.28-7.49(m, 1H), 7.63-7.75(m, 2H), 8.33(d, J-4.8 Hz, 2H).
EXAMPLE 127 1 -f(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine (Compound 127)
a) 2-(2,4-Dimethoxybenzylamino)-3-methoxy-6-methylquinoxaline
To 2-chloro-3-methoxy-6-methylquinoxaline (3.05 g, 14.6 mmol) dissolved in dimethylsulfoxide
(40 ml), 2,4-dimethoxybenzylamine (9.77 g, 58.4 mmol) was added at room temperature. The mixture was

stirred at 60 °C for 45 hours and then water was added thereto. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (13:1) mixture and concentration gave 4.48 g of the titled compound (yield, 90 %).
b) 2-Amino-3-methoxy-6-rnethylquinoxaline
To 2-(2,4-dimethoxybenzylamino)-3-methoxy-6-methylquinoxaline (4.48 g, 13.2 mmol), 30 ml of 50 % trifluoroacetic acid in dichloromethane was added at room temperature. The resulting mixture was stirred at room temperature for 18 hours and concentrated under the reduced pressure to remove the solvent. The residue was neutralized with saturated sodium bicarbonate solution and then NaCl solution was added thereto. The product was extracted with dichloromethanee and the organic layer was dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (3:1) mixture and concentration gave 2.01 g of the titled compound (yield, 81 %).
c) Ethyl Ar-(3-methoxy-6-methylquinoxalin-2-yl)carbamate
2-Amino-3-methoxy-6-methylquinoxaline (1.15 g, 6.08 mmol) and ethyl chloroformate (1.32 g, 12.2 mmol) were dissolved in dichloromethane (30 ml) at room temperature and thereto pyridine (0.96 g, 12.2 mmol) was added. The resulting mixture was stirred at room temperature for 24 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (3:1) mixture and concentration gave 1.59 g of the titled compound (yield, 100 %).
d) l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate (30 mg, 0.11 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 34 mg of the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 5 2.43(s, 3H), 3.22-3.29(m, 4H), 3.73-3.87(m, 4H), 4.13(s, 3H), 6.87-7.74(m, 9H).
EXAMPLE 128
l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 128)

Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1 -(2-methoxyphenyl)piperazine reacted by the same way with the example 127 to obtain the titled compound (yield, 90 %). *H NMR (300 MHz, CDC13): 5 2.49(s, 3H), 3.09-3.18(m, 4H), 3.77-3.82(m, 4H), 3.88(s, 3H), 4.13(s, 3H), 6.87-7.80(m, 8H).
EXAMPLE 129 l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 129)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 89 %). 'H NMR (300 MHz, CDC13): 8 2.49(s, 3H), 3.19-3.32(m, 4H), 3.61-3.90(m, 4H), 3.79(s, 3H), 4.17(s, 3H), 6.44-6.58(m, 4H), 7.00-7.65(m, 3H), 7.72(d, 7=8.2 Hz, 1H).
EXAMPLE 130
1 -f(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 130)
Ethyl Af-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 96 %). *H NMR (200 MHz, CDC13): 8 2.50(s, 3H), 3.15-3.17(m, 4H), 3.68-3.78(m, 4H), 3.78(s, 3H), 4.14(s, 3H), 6.84-7.75(m, 8H).
EXAMPLE 131
l-f(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
131)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 88 %). MS(ESI)m/z438(M+l).
EXAMPLE 132
l-|(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
132)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and
l-(3,4,5-trimethoxyphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 91 %). 'H NMR (300 MHz, CDC13): 8 2.49(s, 3H), 3.16-3.23(m, 4H), 3.71-3.95(m, 4H), 3.80(s, 3H), 3.86(s, 6H), 4.13(s, 3H), 6.19(s, 2H), 7.08-7.62(m, 3H), 7.72(d, .7=8.6 Hz, III).

EXAMPLE 133
l-[(1-3)Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 133)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1-(2-methylphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 84 %). 'H NMR (300 MHz, CDC13): 6 2.35(s, 3H), 2.50(s, 3H), 2.89-3.09(m, 4H), 3.68-3.88(m, 4H), 4.14(s, 3H), 6.99-7.78(m, 7H), 7.76(d, .7=8.0 Hz, 1H).
EXAMPLE 134 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 134)
Ethyl A^-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 91 %). *H NMR (300 MHz, CDC13): 5 2.33(s, 3H), 2.46(s, 3H), 3.21-3.28(m, 4H), 3.72-3.86(m, 4H), 4.13(s, 3H), 6.74-6.78(m, 4H), 7.00-8.01 (m,4H).
EXAMPLE 135 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound 135)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 83 %). 'H NMR (300 MHz, CDC13): 5 2.33-2.50(m, 9H), 3.14-2.20(m, 4H), 3.70-3.75(m, 4H), 4.14(s, 3H), 7.00(s, 3H), 7.09-7.78(m, 3H).
EXAMPLE 136 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound 136)
Ethyl A/-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 95 %). 1H NMR (300 MHz, CDC13): 5 2.29(s, 6H), 2.50(s, 3H), 3.18-3.29(m, 4H), 3.73-3.80(m, 4H), 4.12(s, 3H), 6.58(s, 3H), 7.31(d, J=8.4 Hz, 1H), 7.43(s, 1H), 7.55(s, 1H), 7.72(d, J=8.4 Hz, 1H).
EXAMPLE 137
1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 137)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 87 %). 1H NMR (300 MHz, CDC13): 8 2.49(s, 3H), 3.27-3.35(m, 4H), 3.69-3.89(m, 4H), 4.13(s, 3H), 7.07-7.60(m, 7H) 7.71(d, J=8.2 Hz, 1H).

EXAMPLE 138
1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 138)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2-fluorolphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 98 %). *H NMR (300 MHz, CDC13): 8 2.49(s, 3H), 3.11-3.18(m, 4H), 3.77-3.86(m, 4H), 4.12(s, 3H), 6.95-7.61(m, 7H), 7.73(d, .7=8.6 Hz, 1H).
EXAMPLE 139 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 139)
Ethyl jV-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1 -(4-fluorophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 8 2.47(s, 3H), 3.07-3.17(m, 4H), 3.77-3.87(m, 4H), 4.13(s, 3H), 6.87-8.01(m, 8H).
EXAMPLE 140
l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 140)
Ethyl N(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2-chlorophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 85 %). 'H NMR (300 MHz, CDC13): 8 2.49(s, 3H), 3.08-3.17(m, 4H), 3.73-3.86(m, 4H), 4.13(s, 3H), 7.00-7.65(m, 7H), 7.74(d, J=8.0 Hz, 1H).
EXAMPLE 141 l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 141)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 87 %). 'H NMR (300 MHz, CDC13): 8 2.46(s, 3H), 3.19-3.33(m. 4H), 3.72-3.77(m, 4H), 4.13(s, 3H), 6.79-7.66(m, 7H), 7.7l(d, .7=8.6 Hz, 1H).
EXAMPLE 142 l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 142)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1 -(4-chlorophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 91 %). 1H NMR (300 MHz, CDC13): 8 2.50(s, 3H), 3.18-3.28(m, 4H), 3.73-3.78(m, 4H), 4.14(s, 3H), 6.86(dd, J=12.2 Hz, 2H),
7.00-7.60(m, 5H), 7.71(d, J=8.2 Hz, 1H).

EXAMPLE 143
l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 143)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2-cyanophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 93 %). *H NMR (300 MHz, CDC13): 5 2.47(s, 3H), 3.20-3.28(m, 4H), 3.76-3.96(m, 4H), 4.14(s, 3H), 7.02-7.13(m, 3H), 7.28(s, 1H), 7.49-7.63(m, 4H).
EXAMPLE 144 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 144)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1-(4-acetylphenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 97 %). *H NMR (300 MHz, CDC13): 5 2.17(s, 3H), 2.54(s, 3H), 3.39-3.58(m, 4H), 3.71-3.90(m, 4H), 4.14(s, 3H), 6.89(d, J=6.4 Hz, 211), 7.21 -7.54(m, 4H), 7.90(d, J=6.4 Hz, 2H).
EXAMPLE 145
l-[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 145)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and 1 -(4-nitrophenyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 89 %). 'H NMR (300 MHz, CDC13): 8 2.45(s, 3H), 3.45-3.60(m, 4H), 3.76-3.88(m, 4H), 4.09(s, 3H), 6.85(d, J=6.2 Hz, 2H), 7.03-7.68(m, 4H), 8.16(d, J=6.0 Hz, 2H).
EXAMPLE 146 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 146)
Ethyl Af-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2-pyridyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 88 %). !H NMR (300 MHz, CDC13): 5 2.49(s, 3H), 3.61-3.71(m, 8H), 4.12(s, 3H), 6.66(d, J=8 Hz, 2H), 7.07-7.74(m, 5H), 8.20(dd, J-5.4, 1.8 Hz, 1H).
EXAMPLE 147 1 -[(3-Methoxy-6-methylquinoxalin-2-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 147)
Ethyl N-(3-methoxy-6-methylquinoxalin-2-yl)carbamate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 127 to obtain the titled compound (yield, 79 %). *H NMR (300 MHz, CDC13): 6 2.45(s, 3H), 3.60-3.80(m, 4H), 3.80-4.05(m, 4H), 4.13(s, 3H), 6.52(t, .7=4.5 Hz, 1H), 7.00-7.69(m, 4H), 8.32(d, J=4.5 Hz, 2H).

EXAMPLE 148
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine (Compound 148)
a) 3,6-Dimethoxy-2-(2,4-dimethoxybenzylamino)quinoxaline
To 2-chloro-3,6-dimethoxyquinoxaline (3.87 g, 17.2 mmol) dissolved in dimethylsulfoxide (70 ml), 2,4-dimethoxybenzylamine (6.07 g, 36.3 mmol) was added at room temperature. The mixture was stirred at 60 °C for 118 hours and then water was added thereto. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a «-hexane:ethyl acetate (6:1) mixture and concentration gave 4.69 g of the titled compound (yield, 77 %).
b) 2-Amino-3,6-dimethoxyquinoxaline
To 3,6-dimethoxy-2-(2,4-dimethoxybenzylamino)quinoxaline (4.45 g, 12.8 mmol), 70 ml of 50 % trifluoroacetic acid in dichloromethane was added at room temperature. The resulting mixture was stirred at room temperature for 18 hours and concentrated under the reduced pressure to remove the solvent. The residue was neutralized with saturated sodium bicarbonate solution and then NaCl solution was added thereto. The product was extracted with dichloromethanee and the organic layer was dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate mixture and concentration gave 2.50 g of the titled compound (yield, 95 %).
c) Ethyl Ar-(3,6-dimethoxyquinoxalin-2-yl)carbamate
3-Amino-2,6-dimethoxyquinoxaline (616 mg, 3.00 mmol) and ethyl chloroformate (391 mg, 3.60 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (285 mg, 3.60 mmol) was added. The resulting mixture was stirred at room temperature for 10 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (3:1) mixture and concentration gave 782 mg of the titled compound (yield, 94 %).
d) l-[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-phenylpiperazine
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate (28 mg, 0.10 mmol) and 1-phenylpiperazine (24 mg, 0.15 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (23 mg, 0.15 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiOa column chromatography. Extraction of the residue with
a «-hexane:ethyl acetate (2:1) mixture and concentration gave 36 mg of the titled compound (yield, 91 %).

'H NMR (300 MHz, CDC13): 6 3.27(s, 4H), 3.76(s, 4H), 3.89(s, 3H), 4.12(s, 3H), 6.87-6.96(m, 3H), 7.13(s, 211)7.29-7.3 l(m, 2H), 7.72-7.75(s, 1H).
EXAMPLE 149
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methoxyphenyl)piperazine (Compound 149)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(2-methoxyphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 84 %). 'H NMR (300 MHz, CDC13): 5 3.13-3.16(m, 4H), 3.66-3.78(m, 4H), 3.88(s, 3H), 3.90(s, 3H), 4.12(s, 3H), 6.87-7.14(m, 7H), 7.76(d, J=5.1Hz, 1H).
EXAMPLE 150 1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 1 50)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3-methoxyphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 90 %). *H NMR (300 MHz, CDC13): 5 3.27(s, 4H), 3.75(s, 4H), 3.79(s, 3H), 3.89(s, 3H), 4.12(s, 3H), 6.44-6.57(m, 3H), 7.14-7.22(m, 4H), 7.72-7.75(m, 1H).
EXAMPLE 151 1 -[(3 ,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-methoxyphenyl)piperazine (Compound 151)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1 -(4-methoxyphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 87 %). 'H NMR (300 MHz, CDC13): 8 3.12-3.15(m, 4H), 3.74-3.76(m, 7H), 3.89(s, 3H), 4.1 l(s, 3H), 6.83-6.93(m, 4H), 7.12-7.13(m, 2H), 7.33(s, 1H), 7.72-7.75(m,
EXAMPLE 152
l-|(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound 152)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 86 %). MS(ESI) m/z 454 (M+l).
EXAMPLE 153
1 -[(3 ,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,4,5-trimethoxyphenyl)piperazine (Compound
153)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3,4,5-trimethoxyphenyl)piperazine

were reacted by the same way with the example 148 to obtain the titled compound (yield, 92 %).
EXAMPLE 154 1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-methylphenyl)piperazine (Compound 154)
Ethyl N(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1-(2-methylphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 93 %). 1H NMR (300 MHz, CDC13): 6 2.35(s, 3H), 2,99-3.02(m, 4H), 3.73-3.76(m, 4H), 3.91(s, 3H), 4.15(s, 3H), 7.00-7.22(m, 7H), 7.76-7.79(m, 1H).
EXAMPLE 155
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 155)
Ethyl jV-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 86 %). *H NMR (300 MHz, CDC13): 8 2.33(s, 3H), 3.26-3.29(m, 4H), 3.73-3.77(m, 4H), 3.90(s, 3H), 4.13(s, 3H), 6.73-6.77(m, 3H), 7.13-7.22(m, 4H), 7.74(d, J=9.8 Hz, 1H).
EXAMPLE 156
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2,6-dimethylphenyl)piperazine (Compound 156)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(2,6-dimethylphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 91 %). 'H NMR (300 MHz, CDC13): 5 2.36(s, 6H), 3.17-3.21(m, 4H), 3.68-3.71(m, 4H), 3.91(s, 3H), 4.14(s, 3H), 6.95-7.03(m, 3H), 7.14-7.21(m, 3H), 7.77-7.80(m, 1H).
EXAMPLE 157
l-[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound 157)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 90 %). 1H NMR (300 MHz, CDC13): 8 2.29(s, 6H), 3.26(s, 4H), 3.75(s, 4H), 3.90(s, 3H), 4.14(s, 3H), 6.59(s, 3H), 6.99-7.20(m, zli), 7.73-7.75(m, 1H).
EXAMPLE 158

1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 158)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 83 %). 'H NMR (300 MHz, CDC13): 5 3.28-3.34(m, 4H), 3.75-3.78(m, 4H), 3.90(s, 3H), 4.13(s, 3H), 7.06-7.14(m, 5H), 7.28-7.40(m, 2H), 7.73(d, J=9.9 Hz, 1H).
EXAMPLE 159
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-fluorophenyl)piperazine (Compound 1 59)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1 -(2-fluorophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 95 %). *H NMR (300 MHz, CDC13): 8 3.18(s, 4H), 3.66(s, 4H), 3.78(s, 3H), 4.15(s, 3H), 6.94-7.27(m, 7H), 7.73-7.87(m,
EXAMPLE 160
l-[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-fluorophenyl)piperazine (Compound 160)
Ethyl Af-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1 -(4-fluorophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 92 %). 'H NMR (300 MHz, CDC13): 8 3.17(s, 4H), 3.75(s, 4H), 3.89(s, 3H), 4.12(s, 3H), 6.86-7.01(m, 4H), 7.13(s, 2H), 7.32(s, 1H), 7.72-7.74(m, 1H).
EXAMPLE 161 l-[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-chlorophenyl)piperazine (Compound 161)
Ethyl Af-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1 -(2-chlorophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 89 %). 'H NMR (300 MHz, CDC13): 8 3.13(s, 4H), 3.78(s, 4H), 3.90(s, 3H), 4.12(s, 3H), 6.98-7.37(m, 7H), 7.76(d, .7=9.9 Hz, 1H).
EXAMPLE 162
1 -[(3 ,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 1 62)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1 -(3-chlorophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 85 %). 'H NMR (300 MHz, CDC13): 8 2.29(s, 4H), 3.74(s, 4H), 3.90(s, 3H), 4.13(s, 4H), 6.78-6.89(m, 3H), 7.15-7.27(m, 4H), 7.73(d, J 9.7 Hz, 1H).

EXAMPLE 163
1 -$(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-chlorophenyl)piperazine (Compound 163)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1-(4-chlorophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 93 %). [H NMR (300 MHz, CDC13): 5 3.23(s, 4H), 3.75(s, 4H), 3.90(s, 3H), 4.13(s, 3H), 6.85(d, J=9.0 Hz, 2H), 7.14(s, 2H), 7.20-7.25(m, 3H), 7.71-7.74(m, 1H).
EXAMPLE 164 1 -|(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-cyanophenyl)piperazine (Compound 164)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(2-cyanophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 97 %). 1H NMR (300 MHz, CDC13): 5 2.46(s, 3H), 3.28(s, 4H), 3.86(s, 3H), 4.08-4.19(m, 4H), 7.01-7.08(m, 3H), 7.17-7.37(m, 1H), 7.49-7.61(m,4H)
EXAMPLE 165 1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-acetylphenyl)piperazine (Compound 165)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1-(4-acetylphenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 93 %). *H NMR (300 MHz, CDC13): 8 2.53(s, 3H), 3.48(s, 4H), 3.77(s, 4H), 3.90(s, 3H), 4.13(s, 3H), 6.86(d, J=8.7 Hz, 2H), 7.14-7.28(m, 3H), 7.72(d, .7=8.4 Hz, 1H), 7.89(d, .7=9.0 Hz, 2H).
EXAMPLE 166
l-[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(4-nitrophenyl)piperazine (Compound 166)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1-(4-nitrophenyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 94 %). !H NMR (300 MHz, CDC13): 5 3.57-3.65(m, 8H), 3.90(s, 3H), 4.01(s, 3H), 7.06(d, J=9.4 Hz, 2H), 7.18-7.22(m, 2H), 7.69(d, J-8.6 Hz, 2H), 8.09(d, J=9.4 Hz, 2H), 9.20(s, 1H).
EXAMPLE 167 1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyridyl)piperazine (Compound 167)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and 1-(2-pyridyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 94 %). 'H NMR (300 MHz, CDC13): 6 3.73(m, 8H), 3.91(s, 3H), 4.15(s, 3H), 6.66-6.70(m, 2H), 7.13-7.20(m, 3H),
7.50-7.56(m, 1H), 7.66(d, J=9.0 Hz, 1H), 8.21 (dd, J=5.1 and 1.5 Hz, 1H).

EXAMPLE 168
1 -[(3,6-Dimethoxyquinoxalin-2-yl)aminocarbonyl]-4-(2-pyrimidyl)piperazine (Compound 168)
Ethyl N-(3,6-dimethoxyquinoxalin-2-yl)carbamate and l-(2-pyrimidyl)piperazine were reacted by the same way with the example 148 to obtain the titled compound (yield, 86 %). *H NMR (300 MHz, CDC13): 5 3.67-3.70(m, 4H), 3.90(s, 3H), 3.95-3.97(m, 4H), 4.13(s, 3H), 6.53(t, .7=4.8 Hz, 1H), 7.1 l-7.23(m, 4H), 7.30(d, J=9.3 Hz, 1H), 8.33(d, .7=4.8 Hz, 2H).
EXAMPLE 169
l-[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound
169) 2-Amino-6,7-difluoro-3-methoxyquinoxaline
To 2-amino-3-chloro-6,7-difluoroquinoxaline (610 mg, 2.83 mmol) dissolved in tetrahydrofuran (40 ml), 25 wt % sodium methoxide (6.12 g, 28.3 mmol) in methanol was added at room temperature and stirred further at room temperature for 1.5 hour. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSCU. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 570 mg of the titled compound (yield, 95 %).
b) Ethyl Af-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate
2-Amino-6,7-difluoro-3-methoxyquinoxaline (550 mg, 2.60 mmol) and ethyl chloroformate (564 mg, 5.20 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (411 mg, 5.20 mmol) was added. The mixture was stirred at room temperature for 13 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiOi column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (3:1) mixture and concentration gave 440 mg of the titled compound (yield, 60 %).
c) l-[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate (25 mg, 0.088 mmol) and l-(3-methoxyphenyl)piperazine (35 mg, 0.18 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (28 mg, 0.18 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiOi column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (1:1) mixture and concentration
gave 29 mg of the titled compound (yield, 76 %). 1H NMR (300 MHz, CDC13) 8 3.28-3.30 (m, 4H),

3.76-3.77 (m, 4H), 3.81 (s, 3H), 4.12 (s, 3H), 6.48-6.49 (m, 2H), 6.56-6.58 (m, 1H), 7.20-7.23 (m, 1H), 7.29-)30 (m, 1H), 7.50-7.53 (m, 1H), 7.60-7.62 (m, 1H).
EXAMPLE 170
1-[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
170)
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate and
l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 70 %). MS (ESI) m/z 460 ([M+H]+).
EXAMPLE 171
1 -[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aniinocarbonyl]-4-(3-methylphenyl)piperazine (Compound 171)
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 66 %). !H NMR (300 MHz, CDC13) 6 2.34 (s, 3H), 3.27-3.29 (m,4H), 3.75-3.77 (m, 4H), 4.15 (s, 3H), 6.75-6.78 (m, 4H), 7.18-7.21 (m, 1H), 7.49-7.53 (m, 1H), 7.58-7.62 (m, 1H).
EXAMPLE 172
1-[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
172)
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbaniate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 70 %).1H NMR (300 MHz, CDC13) 5 2.30 (s, 6H), 3.26-3.28 (m, 4H), 3.74-3.76 (m, 4H), 4.15 (s, 3H), 6.59 (s, 3H), 7.29 (s, 1H), 7.49-7.53 (m, 1H), 7.52-7.62 (m, 1H).
EXAMPLE 173
1 -[ (6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 173)
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 59 %). 1H NMR (300 MHz, CDC13) 8 3.33-3.35 (m,4H), 3.70-3.80 (m, 4H), 4.15 (s, 3H), 7.09-7.11 (m, 1H), 7.14-7.16 (m, 2H), 7.26 (s, 1H), 7.38-7.41 (m, 1H), 7.49-7.53 (m, 1H), 7.54 (br s, 1H).
EXAMPLE 174

1 -[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 174)
Ethyl N-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 67 %). *H NMR (300 MHz, CDC13) 5 3.30 (m, 4H), 3.76 (m, 4H), 4.15 (s, 3H), 6.80-6.82 (m, IH), 6.87-6.91 (m, 2H), 7.19-7.22 (m, IH), 7.29 (br s, IH), 7.49-7.51 (m, IH), 7.60 (br s, IH).
EXAMPLE 175
1 -[(6,7-Difluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-bromophenyl)piperazine (Compound 175)
Ethyl Af-(6,7-difluoro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-bromophenyl)piperazine were reacted by the same way with the example 169 to obtain the titled compound (yield, 58 %). 'H NMR (300 MHz, CDC13) 5 3.30 (m, 4H), 3.76 (m, 4H), 4.15 (s, 3H), 6.85-6.87 (m, IH), 7.02-7.03 (m, 2H), 7.06-7.07 (m, IH), 7.13-7.16 (m, IH), 7.30 (br s, IH), 7.51-7.53 (m, IH), 7.60 (br s, IH).
EXAMPLE 176
l-[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound
176) 2-Amino-6,7-dichloro-3-methoxyquinoxaline
To 2-amino-3,6,7-trichloroquinoxaline (1.54 g, 6.20 mmol) dissolved in tetrahydrofuran (40 ml), 25 wt % sodium methoxide (2.01 g, 9.30 mmol) in methanol was added at room temperature and stirred further at room temperature for 1 hour. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSC4 After concentration under the reduced pressure, the crude product was purified by SiCh column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (2:1) mixture and concentration gave 1.21 g of the titled compound (yield, 80 %).
b) Ethyl N-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate
2-Amino-6,7-dichloro-3-methoxyquinoxaline (1.16 g, 4.75 mmol) and ethyl chloroformate (1.03 g, 9.50 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (751 mg, 9.50 mmol) was added. The mixture was stirred at room temperature for 24 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 1.29 g of the titled compound (yield, 86 %).
c) l-f(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine

Ethyl N-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate (28 mg, 0.089 mmol) and l-(3-npethoxyphenyl)piperazine (35 mg, 0.18 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (27 mg, 0.18 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (1:1) mixture and concentration gave 27 mg of the titled compound (yield, 66 %). 1H NMR (300 MHz, CDC13) S 3.28-3.30 (m,4H), 3.74-3.76 (m, 4H), 3.81 (s, 3H), 4.19 (s, 3H), 6.47-6.49 (m, 3H), 6.53-6.57 (m, 1H), 7.30 (br s, 1H), 7.85 (s, 1H), 7.92 (s, 1H).
EXAMPLE 177
1-[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
177)
Ethyl 7V-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate and
1 -(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 68 %). 1H NMR (300 MHz, CDC13) 8 3.28-3.30 (m,4H), 3.74-3.78 (m, 4H), 3.79 (s, 6H), 4.15 (s, 3H), 6.07 (s, 1H), 6.11 (s, 2H), 7.33 (br s, 1H), 7.85 (s, 1H), 7.92 (s, 1H).
EXAMPLE 178
1 -[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 178)
Ethyl Af-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 71 %). 1H NMR (300 MHz, CDC13) 8 2.34 (s, 3H), 3.18-3.21 (m,4H), 3.75-3.79 (m, 4H), 4.14 (s, 3H), 6.75-6.78 (m, 4H), 7.32 (br s, 1H), 7.85 (s, 1H), 7.92 (s, 1H).
EXAMPLE 179
l-[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
179)
Ethyl N-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbarnate and
l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 55 %). !H NMR (300 MHz, CDC13) 8 2.30 (s, 6H), 3.16-3.21 (m,4H), 3.75-3.79 (m, 4H), 4.15 (s, 3H), 6.52-6.59 (m, 3H), 7.31 (br s, 1H), 7.85 (s, 1H), 7.92 (s, 1H).
EXAMPLE 180

1 -[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 180)
Ethyl Af-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 61 %). 1H NMR (300 MHz, CDC13) 8 3.32-3.35 (m,4H), 3.77 (m, 4H), 4.16 (s, 3H), 7.05-7.16 (m, 3H), 7.30 (br s, IH), 7.33-7.39 (m, IH), 7.86 (s, IH), 7.91 (s, IH).
EXAMPLE 181
l-[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 181)
Ethyl A^-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 61 %). 1H NMR (300 MHz, CDC13) 5 3.31-3.30 (m, 4H), 3.75-3.76 (m, 4H), 4.15 (s, 3H), 6.80-6.82 (m, IH), 6.90-6.91 (m, 2H), 7.18-7.23 (m, IH), 7.32 (br s, IH), 7.85 (s, IH), 7.91 (s, IH).
EXAMPLE 182
1 -[(6,7-Dichloro-2-methoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-bromophenyl)piperazine (Compound 182)
Ethyl N-(6,7-dichloro-2-methoxyquinoxalin-3-yl)carbamate and l-(3-bromophenyl)piperazine were reacted by the same way with the example 176 to obtain the titled compound (yield, 72 %). 1H NMR (300 MHz, CDC13) 5 3.29-3.31 (m, 4H), 3.74-3.76 (m, 4H), 4.16 (s, 3H), 6.85-6.87 (m, IH), 7.02-7.04 (m, III), 7.06-7.07 (m, IH), 7.13-7.15 (m, IH), 7.32 (br s, IH), 7.86 (br s, IH), 7.86 (br s, IH), 7.91 (br s, IH).
EXAMPLE 183
l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound
183) 2-Amino-3-methoxy-6,7-dimethylquinoxaline
To 2-amino-3-chloro-6,7-dimethylquinoxaline (2.59 g, 12.5 mmol) dissolved in tetrahydrofuran (40 ml), 25 wt % sodium methoxide (4.05 g, 18.7 mmol) in methanol was added at room temperature and stirred further at room temperature for 1 hour. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with ethyl acetate and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 2.38 g of the titled compound (yield, 94 %).
b) Ethyl Ar-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate

2-Amino-3-methoxy-6,7-dimethylquinoxaline (2.34 g, 11.5 mmol) and ethyl chloroformate (2.50 g, 23.£tmmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (1.82 g, 23.0 mmol) was added. The mixture was stirred at room temperature for 12 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (3:1) mixture and concentration gave 2.65 g of the titled compound (yield, 84 %).
c) l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine
Ethyl N-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate (35 mg, 0.13 mmol) and l-(3-methoxyphenyl)piperazine (50 mg, 0.26 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (40 mg, 0.26 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 37 mg of the titled compound (yield, 68 %). 1E NMR (300 MHz, CDC13) 8 2.33 (s, 3H), 2.39 (s, 3H), 3.22-3.30 (m,4H), 3.75 (m, 4H), 3.80 (s, 3H), 4.13 (s, 3H), 6.46-6.49 (m, 2H), 6.55-6.58 (m, 1H), 7.20-7.23 (m, 1H), 7.52 (s, 1H), 7.60 (s, 1H).
EXAMPLE 184 l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound
184)
Ethyl N-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and
1 -(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 75 %). 1H NMR (300 MHz, CDC13) 5 2.33 (s, 3H), 2.39 (s, 3H), 3.21-3.29 (m,4H), 3.75 (m, 4H), 3.79 (s, 3H), 4.11-4.13 (m, 3H), 6.06 (s, 1H), 6.12 (s, 2H), 7.52 (s, 1H), 7.59 (s, 1H).
EXAMPLE 185
1 -[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 185)
Ethyl A^-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 49 %). 1H NMR (300 MHz, CDC13) 5 2.33 (s, 6H), 2.40 (s, 3H), 3.21-3.31 (m,4H), 3.74-4.11 (m, 3H), 4.13 (s, 4H), 6.71-6.78 (m, 3H), 7.16-7.20 (m, 1H), 7.36 (br s, 1H), 7.52 (s, 1H), 7.60 (s, 1H).
EXAMPLE 186
l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound
186)

Ethyl Ar-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and
l-(3,5diMethylphenyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 58 %). 'H NMR (300 MHz, CDC13) 5 2.29-2.40 (m, 12H), 3.20-3.29 (m,4H), 3.80-3.83 (m, 3H), 4.10 (s, 4H), 5,12 (br s, 1H), 6.59 (s, 3H), 7.36-7.60 (m, 2H).
EXAMPLE 187
l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound
187)
Ethyl N-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 63 %). *H NMR (300 MHz, CDC13) 5 2.33-2.40 (m, 6H), 3.27-3.38 (m,4H), 3.78-3.79 (m, 3H), 4.13 (s, 4H), 7.08-7.14 (m, 2H), 7.36-7.40 (m, 2H), 7.53 (s, 1H), 7.59 (s, 1H).
EXAMPLE 188
l-[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound
188)
Ethyl N-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 71 %). 1H NMR (300 MHz, CDC13) 5 2.33 (s, 3H), 2.40 (s, 3H), 3.23-3.30 (m, 4H), 3.74-3.77 (m, 3H), 4.13 (s, 4H), 6.80-6.91 (m, 3H), 7.15-7.20 (m, 1H), 7.36 (br s, 1H), 7.53 (s, 1H), 7.59 (s, 1H).
EXAMPLE 189
1 -[(2-Methoxy-6,7-dimethylquinoxalin-3-yl)aminocarbonyl]-4-(3-bromophenyl)piperazine (Compound 189)
Ethyl N-(2-methoxy-6,7-dimethylquinoxalin-3-yl)carbamate and l-(3-bromophenyl)piperazine were reacted by the same way with the example 183 to obtain the titled compound (yield, 69 %). 'H NMR (300 MHz, CDC13) 8 2.33 (s, 3H), 2.40 (s, 3H), 3.22-3.31 (m, 4H), 3.73-3.76 (m, 3H), 4.13 (s, 4H), 6.85 (m, 1H), 7.00-7.20 (m, 3H), 7.40 (br s, 1H), 7.53 (s, 1H), 7.59 (s, 1H).
EXAMPLE 190
1 -[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine (Compound 190)
a) 2-Amino-3,6,7-trimethoxyquinoxaline

To 2-amino-3-chloro-6,7-dimethoxyquinoxaline (3.27 g, 13.6 mmol) dissolved in tetrahydrofuran (40 m) 25 wt % sodium methoxide (4.41 g, 20.4 mmol) in methanol was added at room temperature and stirred further at room temperature for 2 hour. The resulting mixture was concentrated under the reduced pressure to remove the solvent. The product was extracted with dichloromethane and the organic layer was washed with water and dried over MgSO4. After concentration under the reduced pressure, the crude product was purified by SiO2 column chromatography. Extraction of the residue with a n-hexane: ethyl acetate (2:1) mixture and concentration gave 2.73 g of the titled compound (yield, 85 %).
b) Ethyl Ar-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate
2-Amino-3,6,7-trimethoxyquinoxaline (2.60 g, 11.0 mmol) and ethyl chloroformate (2.40 g, 22.1 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (1.75 g, 22.1 mmol) was added. The mixture was stirred at room temperature for 22 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiOi column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (2:1) mixture and concentration gave 3.04 g of the titled compound (yield, 90 %).
c) l-[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methoxyphenyl)piperazine
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate (28 mg, 0.091 mmol) and l-(3-methoxyphenyl)piperazine (27 mg, 0.18 mmol) were dissolved in tetrahydrofuran (2 ml) at room temperature and thereto DBU (27 mg, 0.18 mmol) was added. The resulting mixture was stirred at 70 °C for 7 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (1:2) mixture and concentration gave 26 mg of the titled compound (yield, 64 %). *H NMR (300 MHz, CDC13) 5 3.27-3.29 (m,4H), 3.78-3.81 (m, 7H), 3.94 (s, 3H), 3.97-3.98 (m, 1H), 4.00 (s, 3H), 4.15 (s, 3H), 6.47-6.49 (m, 2H), 6.56-6.58 (m, 1H), 7.11 (s, 1H), 7.14-7.27 (m, 3H).
EXAMPLE 191 l-[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethoxyphenyl)piperazine (Compound 191)
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethoxyphenyl)piperazine were reacted by the same way with the example 190 to obtain the titled compound (yield, 68 %). 'H NMR (300 MHz, CDC13) 5 3.28-3.29 (m,4H), 3.75-3.79 (m, 4H), 3.97 (s, 3H), 4.00 (s, 3H), 4.13 (s, 3H), 6.07-6.11 (m, 3H), 7.14 (s, 1H), 7.27-7.28 (m, 2H).
EXAMPLE 192
1 -[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-methylphenyl)piperazine (Compound 192)

Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3-methylphenyl)piperazine were reactedy the same way with the example 190 to obtain the titled compound (yield, 56 %). 'H NMR (300 MHz, CDC13) 8 2.34 (s, 3H), 3.25-3.30 (m,4H), 3.76-3.80 (m, 4H), 3.98 (s, 3H), 4.02 (s, 3H), 4.16 (s, 3H), 6.74-6.78 (m, 3H), 7.14-7.26 (m, 4H).
EXAMPLE 193
1 -[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3,5-dimethylphenyl)piperazine (Compound 193)
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3,5-dimethylphenyl)piperazine were reacted by the same way with the example 190 to obtain the titled compound (yield, 56 %). 1H NMR (300 MHz, CDC13) 8 2.28 (s, 3H), 2.30 (s, 3H), 3.26 (m,4H), 3.77 (m, 4H), 3.97 (s, 3H), 4.00 (s, 3H), 4.13 (s, 3H), 6.59 (s, 3H), 7.14 (s, IH), 7.27 (s, IH).
EXAMPLE 194
1 -[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-trifluorotolyl)piperazine (Compound 194)
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3-trifluorotolyl)piperazine were reacted by the same way with the example 190 to obtain the titled compound (yield, 67 %). 'H NMR (300 MHz, CDC13) 8 3.34 (m,4H), 3.81 (m, 4H), 3.97 (s, 3H), 4.00 (s, 3H), 4.13 (s, 3H), 7.09-7.11 (m, 2H), 7.14 (s, 3H), 7.25 (m, IH), 7.38-7.41 (m, IH).
EXAMPLE 195 1 -[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-chlorophenyl)piperazine (Compound 195)
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3-chlorophenyl)piperazine were reacted by the same way with the example 190 to obtain the titled compound (yield, 74 %). !H NMR (300 MHz, CDC13) 8 3.29-3.31 (m, 4H), 3.79 (m, 4H), 3.97 (s, 3H), 4.00 (s, 3H), 4.12 (s, 3H), 6.82 (m, IH), 6.86-6.88 (m, IH), 6.89-6.91 (m, IH), 7.14 (s, IH), 7.19-7.22 (m, 3H).
EXAMPLE 196 1-[(2,6,7-Trimethoxyquinoxalin-3-yl)aminocarbonyl]-4-(3-bromophenyl)piperazine (Compound 196)
Ethyl N-(2,6,7-trimethoxyquinoxalin-3-yl)carbamate and l-(3-bromophenyl)piperazine were reacted by the same way with the example 190 to obtain the titled compound (yield, 63 %). 1H NMR (300 MHz, CDC13) 8 3.28-3.30 (m, 4H), 3.78 (m, 4H), 3.97 (s, 3H), 3.99 (s, 3H), 4.13 (s, 3H), 6.86 (m, IH), 7.01 (s, IH), 7.06-7.07 (m, IH), 7.13-7.16 (m, 2H), 7.22-7.28 (m, 2H).
The structures of compound 1 to 196 are presented in the following Table la-If.

[Table la-If]
(Table Removed)


The followings illustrate representative pharmaceutical dosage forms containing the compound of formula (1), or-pharmaceutically acceptable salt thereof (hereafter compound X) for therapeutic or prophylactic use in humans. The formulations may be obtained by conventional procedures well known in the pharmaceutical art and are not limited to the representative pharmaceutical dosage forms.
1) Tablet (Direct pressure)
5.0 mg of sieved compound X was mixed with 14.1 mg of lactose, 0.8 mg of Crosspovidone USNF and 0.1 mg of magnesium stearate and the mixture was compressed into tablets.
2) Tablet (Hydroassembly)
5.0 mg of sieved compound X was mixed with 16.0 mg of lactose and 4.0 mg of starch and 0.3 mg of polysorbate 80 dissolved in pure water was added thereto. After making particle with the mixture, the particle was dried, sieved and mixed with 2.7 mg of colloidal silicon dioxide and 2.0 mg of magnesium stearate. The particle was compressed into tablets.
3) Powder and capsule
5.0 mg of sieved compound X was mixed with 14.8 mg of lactose, 10.0 mg of polvinylpolypyrrolidone and 0.2 mg of magnesium stearate and the mixture was filled into No.5 gelatin capsule using suitable equipment.
4) Injection
100 mg of compound X, 180 mg of mannitol and 26 mg of Na2HPO4 12H2O were dissolved in 2974 ml of distilled water.
Biological Tests 1. Growth of cancer cell lines
Cancer cells used in this study to determine the effect of quinazoline compounds were obtained from the following sources: Human OVCAR-3 (ovary), MCF-7 (breast, hormone-dependent), MDA-MB-231 (breast), PC3 (prostate), HepG2 (liver), A549 (lung), Caki-1 (kidney), HT-29 (colon), HCT116 (colon) and PANC-1 (pancreas) from the American Type Culture Collection (ATCC) (Manassas, VA); MKN-45 (stomach) from DSMZ (Germany); UMRC2 (kidney) from the U. S. National Cancer Institute (Bethesda, MD); Huvec (human umbilical vein endothelial cells), HEK293 (human embryonic kidney) and SK-OV-3 (ovary) from Korean Cell Line Bank (Seoul, Korea). OVCAR-3, MCF-7, PC3, HepG2, A549, HT-29 and MKN-45 were grown in RPMI1640 medium (Invitrogen, Carlsbad, CA) supplemented with 10 % fetal bovine serum ("FBS"), 1 mM sodium pyruvate, 10 mM HEPES and 100 U/ml penicillin and 100 ug/ml streptomycin ("P/S"). MDA-MB-231, HCT116, UMRC2, Caki-1, PANC-1
and HEK293 cells were maintained in Dulbecco's modified Eagle's medium ("DMEM", Invitrogen)

supplemented with 10 % FBS, P/S, 10 mM HEPES and 2 mM L-glutamine. HUVEC was maintained in Ml99 Supplemented with basic fibroblast growth factor ("bFGF") 3 mg/ml, Heparn 100 mg/ml and FBS 20 %. All cells were incubated at 37 °C under humidified 5 % CO2.
2. Cell Growth Inhibition Assay
The growth inhibition of the substituted quinoxalin-piperazine compounds against a variety of human tumor cells was evaluated. The relative importance of particular substituent groups on the compounds was also studied. The substituted piperazinee derivative compounds, prepared as described above, were tested, along with DMSO as a control.
The growth inhibition assay of various compounds against human tumor cell lines was performed using the Sulforhodamine B ("SRB") method (Skehan et al., J. National Cancer Institute, 1990, 82, 1107-1112). Briefly, exponentially growing tumor cells were seeded into a 96-well plate at a density of 2 ~ 3 x 103 cells/well and treated with quinazoline compounds the next day. Triplicate wells were used for each treatment. The cells were incubated with the various compounds for 96 hours at 37 °C in a humidified 5 % CO2 atmosphere. After 96-hour incubation, cells were fixed with 10 % trichloroacetic acid ("TCA"), incubated for 1 hour at 4 °C, and washed 3 times with tap water. Subsequently cells were stained with 0.4 % sulforhodamine B in 1 % acetic acid for 30 minutes, washed 4 times with 1 % acetic acid, and air-dried again. After 5 minutes agitation in 10 mM Tris solution, the absorbance of each well was measured at 530 nm using Benchmark Plus Microplate reader (Bio-Rad Laboratories, Hercules, CA).
To translate the ODsso values into the number of live cells in each well, the ODsso values were compared to those on standard ODsso - versus - cell number curves generated for each cell line. The percent survival was calculated using the formula:
% Survival = live cell number [test] /live cell number [control] x 100
The ICso values were calculated by non-linear regression analysis.
Using QSAR and combinatorial chemistry techniques, a large number of compounds, including the compounds shown in Table la-If above, were synthesized. The synthesized compounds were screened against at least three cell lines, PANC-1, MDA-MB-231 and UMRC2, at approximately luM concentration. Compounds showing activity in at least one of these cell lines were selected for further screening. From these compounds, fifty compounds were selected for further evaluation as broad spectrum anti-proliferative agents as shown in the following Table 2a-2b.
[Table 2a-2b]

(Table Removed)

Industrial Applicability
The novel compounds of the present invention may provided novel quinoxaline-piperazine derivatives or pharmaceutically acceptable salts thereof which have the strong anti-proliferative effect and are useful for treating hyperproliferative disorders, including cancers, by administering quinoxaline-piperazine compounds.


(Revised Version)





We Claim:
1. A compound of the general formula (1), 1-[(6,7-substituted
alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives and
their pharmaceutically acceptable salts thereof,
(Formula Removed)
wherein X and Y are independently N or C-R7; R1 and R2 are independently hydrogen, C1-C3 alkoxy, C1-C3 alkyl or halogen; R3 is C1-C3 alkyl; R4, R5, R6 and R7 are independently hydrogen, C1-C3 alkoxy, C1-C3 alkyl, C1-C3 haloalkyl, C1-C3 alkylcarbonyl, halogen, cyano or nitro.
2. The compound of the formula (1) as claimed in claim 1, wherein X and Y are independently N, C-H, C-F, C-CI, C-CN, C-CH3 or C-OCH3.
3. The compound of the formula (1) as claimed in claim 1, wherein R1 and R2 are independently hydrogen, F, CI, methyl or methoxy
4. The compound of the formula (1) as claimed in claim 1, wherein R3 is methyl.
5. The compound of the formula (1) as claimed in claim 1, wherein R4, R5 and R6 are independently hydrogen, CI, Br, nitro, methyl, trifluoromethyl, methoxy or acetyl.
6. The compound of the formula (1) as claimed in claim 1 wherein R7 is hydrogen, F, CI, cyano, methyl or methoxy.
7. A process for the preparation of 1-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives, comprising
reacting a compound of the general formula (6) with 2,4-dimethoxybenzylamine in an amount of 1.0-5.0 equivalents under

dimethylsulfoxide as a solvent to give a compound of the general formula
(7); and
reacting a compound of the general formula (7) with trifluoroacetic acid
(TFA) under dichloromethane as a solvent to give a compound of the
general formula (2); and
reacting a compound of the general formula (2), 6,7-substituted-2-alkoxy-3-
aminoquinoxaline, with an L-C(=O)-L' in the amount 1.0-1.5 equivalents
indicated group-providing agent under a conventional organic solvent in the
presence of a base at room temperature to 100 °C to obtain a compound of
the general formula (3); and
successively reacting the compound of the general formula (3) with a
compound of the general formula (4), 1-(hetero)arylpiperazine derivatives in
the amount of 1.0-1.5 equivalents under a conventional organic solvent in
the presence of a base at 50 °C to 100 °C, to give the compound of the
general formula (1);
(Formula Removed)
wherein X, Y, R1, R2, R3, R4, R5 and R6 are the same as defined in claim 1, and L and L' are independently imidazole, CI, ethoxy, phenoxy or 4-nitrophenoxy.
8. A compound of the general formula (2), 6,7-substituted-2-alkoxy-3-
aminoquinoxaline
(Formula Removed)
wherein R1, R2 and R3are the same as defined in claim 1.
9. A pharmaceutical composition which comprises a compound of the general
formula (1), 1-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-
(hetero)arylpiperazine derivatives and their pharmaceutically-acceptable salts
therof, as claimed in claim 1 in association with a pharmaceutically-
acceptable diluent or carrier.
10. A method for producing an anti-proliferative effect in a warm-blooded animal,
such as human, in need of such treatment which comprises administering to
said animal an effective amount of a quinaxoline-piperazine derivative of the
formula (1), 1-[(6,7-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-
(hetero)arylpiperazine derivatives and their pharmaceutically-acceptable salts
thereof, as claimed in claim 1.
11. A compound of the general formula (1) substantially as herein described with
reference to the foregoing description, examples and the accompanying
tables.
12. A process for the preparation of 1-[(6,7-substituted
alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives
substantially as herein described with reference to the foregoing description,
examples and the accompanying tables.
13. A compound of the general formula (2) substantially as herein described with
reference to the foregoing description, examples and the accompanying
tables.
14. A pharmaceutical composition which comprises a compound of the general
formula (1) substantially as herein described with reference to the foregoing
description, examples and the accompanying tables.
15. A method for producing an anti-proliferative effect in a warm-blooded animal substantially as herein described with reference to the foregoing description, examples and the accompanying tables.

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Patent Number 277210
Indian Patent Application Number 3673/DELNP/2007
PG Journal Number 48/2016
Publication Date 18-Nov-2016
Grant Date 15-Nov-2016
Date of Filing 17-May-2007
Name of Patentee REXAHN PHARMACEUTICALS, INC.
Applicant Address 9620 MEDICAL CENTER DRIVE, ROCKVILLE, MD 20850, USA.
Inventors:
# Inventor's Name Inventor's Address
1 GONG,YOUNG-DAE 113-505 HANBIT APT., 99 EOEUN-DONG, YUSEONG-GU, DAEJEON 305-755, REPUBLIC OF KOREA
2 JEON, MOON-KOOK 301 HANBIT VILLA, 148-6 SINSEONG-DONG, YUSEONG-GU, DAEJEON 305-345, REPUBLIC OF KOREA
3 KIM, DONG-SU 72-311 GARAK APT., GARAK-DONG, SONGPA-GU, SEOUL 138-160, REPUBLIC OF KOREA
4 KIM, GUN-DO 406-1508 EXPO APT., JEONMIN-DONG, YUSEONG-GU, DAEJEON 305-762, REPUBLIC OF KOREA
5 KONG, JAE YANG 109-1503 EXPO APT., JEONMIN-DONG, YUSEONG-GU, DAEJEON 305-761, REPUBLIC OF KOREA
6 AHN, CHANG-HO 9620 MEDICAL CENTER DRIVE, ROCKVILLE, MD 20850, USA
7 LEE, YOUNG BOK 9620 MEDICAL CENTER DRIVE, ROCKVILLE, MD 20850, USA
PCT International Classification Number C07D 403/12
PCT International Application Number PCT/KR2005/003463
PCT International Filing date 2005-10-18
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10-2004-0094232 2004-11-17 Republic of Korea
2 10-2004-0094233 2004-11-17 Republic of Korea