Title of Invention

"NEW PYRIMIDINE LINKED PYRROLO[2,1-c][1,4]BENZODIAZEPINES AS PONTENTIAL ANTITUMOUR AGENTS"

Abstract The present invention relates to a process for the preparation of novel pyrrolo [2,1- c][l,4]benzodiazepines useful as potential antitumour agents. This invention also relates to a process for the preparation of new pyrrolo[2,l-c][l,4]benzodia2epines as potential antitumour agents. More particularly, it provides a process for the preparation of 7-methoxy-8-[6'-(4"- fluorophenyl)-2'-methylpyrimidine-4'-yloxy] alkoxy-(l laS)-l,2,3,1 la-tetrahydro-5H- pyrrolo[2,l,c][l,4]ben2odiazepin-5-one with ahphatic chain length variations for the compounds and it also describes the anticancer (antitumour) activity. The structural formula of novel pyrrolo [2,1-c] [l,4]benzodiazepine is as follows.
Full Text NEW PYRIMIDINE LINKED PYRROLO[2,l-cl[l,41BENZODIAZEPINES AS POTENTIAL ANTITUMOUR AGENTS
Field of the invention
The present invention relates to a process for the preparation of novel pyrimidine linked pyrrolo [2,l-c][l,4]benzodiazepines useful as potential antitumour agents. This invention also relates to a process for the preparation of new pyrimidine linked pyrrolo[2,l-c][l,4]benzodiazepines as potential antitumour agents. More particularly, it provides a process for the preparation of 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy] alkoxy-(llaS)-l,2,3,1 la-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one with aliphatic chain length variations for the compounds and it also describes the anticancer (antitumour) activity. The structural formula of novel pyrrolo[2,l-c] [l,4]benzodiazepine is as follows.
(Formula Removed)
Background of the invention
Pyrrolo[2,l-c][l,4]benzodiazepines anti-tumour antibiotics are commonly known as anthramycin class of compounds. In the last few years, a growing interest has been shown in the development of new pyrrolo[2,l-c][l,4]benzodiazepines (PBDs). These antibiotics react covalently with DNA to form an N2-guanine adduct that lies within the minor groove of duplex DNA via an acid-labile aminal bond to the electrophilic imine at the NIO-C11 position (Kunimoto, S.; Masuda, T.; Kanbayashi, N.; Hamada, M.; Naganawa, H.; Miyamoto, M.; Takeuchi, T.; and Unezawa, H. J. Antibiot., 1980, 33, 665.; Kohn, K. W. and Speous, C. L. J. Mol Biol, 1970, 51, 551.; Hurley, L. H.; Gairpla, C. and Zmijewski, M. Biochem. Biophys. Acta., 1977, 475, 521.; Kaplan, D. J. and Hurley, L. H. Biochmestry, 1981, 20, 7572). The molecules have a right-handed twist, which allows them to follow the curvature of the minor groove of B-form double-stranded DNA spanning three base pairs. Recently, PBD dimers have been developed that comprises two C2-exo-methylene-substituted DC-81 subunits tethered through their C-8 position via an inert propanedioxy linker (Gregson, S. J.; Howard, P. W.; Hartely, J. A.; Brooks, N. A.; Adams, L. J.; Jenkins, T. C; Kelland, L. R. and Thurston, D. E. J.MedChem. 2001, 44, 737). A recent development
has been the Unking of two PBD units through their C-8 positions to give bisfunctional alkylating agents capable of cross-linking DNA (Thurston, D. E.; Bose, D. S,; Thomson, A. S., Howard, P. W.; Leoni, A.; Croker, S. J,; Jenkins, T. C; Neidle, S. and Hurley, L. H. J. Org. Chem., 1996, 6J, 8141-8147). Recently, a non -crass - linking - mixed imine -amide PBD dimers have been synthesized which have significant DNA binding ability and potent anti tumour activitiy. (Kamal, A.; Ramesh, G.; Laxman, N.; Ramulu, p.; Srinivas, O.;
Neelima, K.; Kumar, K.K.; Srinu, V.B., Nagarajaram, H.M. J. Med. Chem. 2002, 45, 4679).
(Formula Removed)
Naturally occurring pyrrolo[2,l-c][l,4]benzodiazepines belong to a group of antitumour antibiotics derived from Streptomyces species. Recently, there is much impetus for the PBD systems as they can recognize and bind to specific sequence of DNA. Examples of naturally occurring PBD's include anthramycin, DC-81, tomaymycin, sibiromycin and neothramycin. However, the clinical efficacy for these antibiotics is hindered by several limitations, such as poor water solubility and cardiotoxicity and development of drug resistance and metabolic inactivation. Objects of the invention
The main object of the present invention is to provide new pyrrolo[2,l-c][l,4] benzodiazepines usefiil as antitumour agents.
Another object of the present invention is to provide a process for the preparation of novel pyrrolo[2,l-c][l,4] benzodiazepines useful as antitumour agents. Accordingly the present invention provides a process for the preparation of a novel pyrrolo[2,l-c][l,4]benzodiazepine of formula VI wherein R = H, OH, OAc and n is 3 - 5.
(Formula Removed)
The present invention also provides a process for preparation of pyrrolo[2,l-c][l,4]benzodiazepines of formula VI of the drawing accompanying the specification wherein R==H, OH, OAc and n is 3 - 5 which comprises reacting 6-4-(4-fluorophenyl)-2-methyl-4-pyrimidinol of formula I with dibromoalkanes in an aprotic water miscible organic solvents like acetone, THF and DMF in presence of mild inorganic bases like K2CO3, CSCO3 and BaCO3 upto refluxing temperature for a period up to 48 h, isolating n-bromoalkyl-6-(4-flurophenyl)-2-methyl-4-pyrimidinyl ether of formula II with (25)-N-(4-hydroxy-5-methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula III in presence of mild inorganic bases like K2CO3. CsCO3, and BaCO3 in presence of aprotic water miscible organic solvents upto refluxing for a period of 48 h isolating (25)-N-[{4-[6'-(4-fluorophenyl)-2-methylpyrimidine-4-yloxy]alkoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxal dehyde diethyl thioacetal IV where n is 3 - 5 by conventional methods, reducing the above nitro compounds of formula IV with SnCl2.2H20 in presence of organic solvent up to a reflux temperature, isolating the (25)-N-[{4-[6'-(4"-fluorophenyl)-2-methylpyrimidine-4-yloxy]alkoxy}-5-methoxy-2-amonobenzoyl]pyrrolidine-2-carbo xaldehyde diethyl thioacetal of formula V where n is 3-5 by known methods, reacting the above said amino compound of formula V with known deprotecting agents in a conventional manner to give novel pyrrolo[2,l-c][l,4]benzodiazepines of formula VI wherein n are as stated above.
The precursor, (25)-N-(4-hydroxy-5-methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula I (intermediates of DC-81) prepared by
literature methods (Thurston, D. E.; Murthy, V. S.; Langley, D. R.; Jones, G. B. Synthesis,
1990, 81)
Detailed description of the invention
Some representative compounds of fonnula VI present invention are given below:
1. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy-(llaS)-1,2,3,11 a-tetrahydro-5H-pyrrolo[2,1 ,c][ l,4]benzodiazepin-5-one.
2. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy-(llaS)-1,2,3, lla-tetrahydro5H-pyrrolo[2,l,c][l,4]ben2odiazepin-5-one.
3. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy-(llaS)-1,2,3,11 a-tetrahydro-5H-pyrrolo[2,1 ,c][ 1,4]benzodiazepin-5-one.
4 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy-(4R)-hydroxy-(llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one
5. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy-(4R)-hydroxy-(l 1 aS)-1,2,3,11 a-tetrahydro-5H-pyrrolo[2,1 ,c][ 1,4]benzodiazepin-5-one
6. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy-(4R)-hydroxy-(llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one
7. 7-methoxy-8-[6' -(4"-fluorophenyl)-2' -methylpyrimidine-4' -yloxy]propoxy-(4R)-acetyloxy-(l laS)-1,2,3,1 la-tetrahydro-5H-pyrroIo[2, l,c][l,4]benzodiazepin-5-one
8. 7-methoxy-8-[6' -(4"-fluorophenyl)-2' -methylpyrimidine-4' -yloxy]butoxy-(4R)-acetyloxy-( 11 aS)-1,2,3,11 a-tetrahydro-5H-pyrrolo[2,1 ,c][ 1,4]benzodiazepin-5-one
9. 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy- (4R) -acetyloxy-(l laS)-l,2,3,1 la tetrahydro5H-pyrrolo[2, l,c][l,4]benzodiazepin-5-one. These new analogues of pyrrolo[2,l-c][l,4]benzodiazepine hybrids hnked at C-8
position have shown promising anticancer activity in various cell lines. The molecules synthesized are of immense biological significance with potential sequence selective DNA-binding property. This resulted in design and synthesis of new congeners as illustrated in Scheme-1, which comprise:
1. ether linkage at C-8 position of DC-81 intermediates with pyrimidine ring moiety.
2. Refluxing the reaction mixture for 24-48 h.
3. Synthesis of C-8 linked PBD antitumour antibiotic hybrid imines.
4. Purification by column chromatography using different solvents like ethyl acetite, hexane, dichloromethane and methanol.
The following examples are given by way of illustration and therefore should not be construed as limiting the scope of invention.
((SCHEME REMOVED)
Example 1
Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg 4.90 mraol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.7 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which
was further purified by column chromatography on silica gel eluting with EtOAc-hexane (5:95) gave the pure 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II, 1H NMR: (CDCI3) 2.1-2.2 (q, 2H), 2.6 (s, 3H), 4.1-4.15 (t, 2H), 4.45-4.55 (t, 2H), 6.6-6.8 (d, 1H), 7.08-7.12 (m, 2H), 8.0 (m, 2H); EIMS 204.
Solution of 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of
formula II (1200 mg, 3.69 mmol), A solution of (25)-N-(4-hydroxy-5-methoxy-2-
nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472 mg, 3.69
mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for 48 h.
After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave the pure (25)-N- [{4-[6'-(4"-fluorophenyl)-2'-
methylpyrimidine-4'-yloxy]-propoxy}-5-methoxy-2-nitro benzoyl] pyrrolidine-2-
carboxaldehyde diethyl thioacetal of formula IV. 1H NMR: (CDCI3) 6 1.2-1.4 (m, 6H), 1.7-2.42 (m, 6H), 2.65 (s, 3H), 2.65-2 8 (m, 4H), 3 2- 3.3 (m, 2H), 3.95 (s, 3H), 4.3 (m, 2H), 4.6 (m, 2H), 4.65-4.8 (m, IH), 4.85 (d, IH J - 4.2), 6.78 (s, IH), 6.9 (s, IH), 7.1-7.2 (m, 2H), 7.7 (s, IH), 8.0-8.1 (m, 2H); FABMS 939 (M+H)+.
(25)-N-[ {4-[6' -(4"-fluoropheny l)-2' -methylpyrimidine-4' -yloxyjpropoxy} -5 -methoxy -2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (500 mg, 0.78 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H20 (873 mg 3.88 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCOs solution and then extracted with ethyl acetate (3x30 mL). The combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford the crude (25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy}-5-methoxy-2-aminobenzoyl]pyrrolidine-2-carbo xaldehyde diethyl thioacetal of formula V.
A solution of formula V (300 mg, 0.50 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOs yas added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy-(llaS)-l,2,3,1 la-tetrahydro-5H-pyrrolo[2,l,c ][1 ,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of
mercuric salts and further eluted with EtOAc-methanol (9:1). 1H NMR: (CDCI3) 5 1.9-2.15 (m, 4H), 2.25-2.4 (m, 2H), 2.65 (s, 3H), 3.5-3.8 (m, 3H), 3.95 (s, IH), 4.0-4.2 (m, 2H), 4.5 (m, 2H), 6.78 (s, IH), 6.8 (s, 1H), 7.1-7.2 (m, 2H), 7.5 (s, 1H), 7.5 (d, 1H, J = 4.3 Hz), 7.95-8 2 (m, 2H); FABMS: 631 (M+H)+ .
Example 2 A solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg 4.90 mmol), 1, 4-dibromobutane (2650 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (4:96) gave the pure 4-bromobutyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II. 1HNMR: (CDCI3) 5 1.9-2.1 (m, 4H), 2.6-2.7 (s, 3H), 3.45-3.55 (t, 2H), 4.4-4.5 (t, 2H), 6.8 (s, IH), 7.1-7.2 (m, 2H), 8.0-8.1 (m, 2H); EIMS 204.
Solution of 4-bromobutyl-6-(4-fluoro nhenyl)-2-methyl-4-pyrimidyl ether of formula II (1300 mg, 3.83 mmol), A solution of (25)-N-(4-hydroxy-5-methoxy-2~ nitrobenzoyl)pyrrohdine-2-carbox-aldehyde diethylthioacetal of formula III (1532 mg, 3.83 mmol) and K2CO3 (1585 mg, 11.47 mmol) in dry acetone (20 ml) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (30:70) gave the pure (25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV. 1H NMR: (CDCl3) 5 1.9-2.15 (m, 6H), 2.25-2.40 (m, 2H), 2.65 (s, 3H), 3.5-3.8 (m, 3H), 3.95 (s, 1H), 4.0-4.2 (m, 2H), 4.50 (m, 2H), 6.78 (s, 1H), 6.80 (s, 1H), 7.1-7.2 (m, 2H), 7.5 (s, 1H), 7.65 (d, 1H, J = 4.4 Hz) 7.95-8.10 (m, 2H); FABMS 939 (M+H)+.
(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy)-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (500 mg, 0.76 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (855 mg 3.80 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCOs solution and then extracted with ethyl acetate (3x30 mL). The combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford the crude (25)-N-[{4-

[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy}-5-methoxy-2-aminobenzoyl]pyrrohdine-2-carbox aldehyde diethyl thioacetal of formula V.
Solution of formula V (300 mg, 0.50 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOs was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy-(llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtOAc-methanol (97:3). 'HNMR (CDCI3) 5 1.92-2.42 (m, 8H), 2.60-2.95 (m, 12H), 3.2-3.88 (m, 6H), 3.92 (s, 6H), 4.14-4.28 (m, 4H), 6.76 (s, 2H), 7.5 (s, 2H), 7.66 (d, 2H); FABMS: 631 (M+H)+
Example 3
Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg 4.90 mmol), 1, 5-dibromopentane (2820 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (3:97) gave the pure 5-bromopentyl-6-(4-fluoro phenyI)-2-methyl-4-pyrimidyl ether of formula II 1HNMR: (CDCis) 1.5-1.6 (q, 2H), 1.7-1.8 (q, 2H), 1.9-2.0 (q, 2H), 2.6 (s, 3H), 3.4 (t, 2H), 4.3-4.4 (t, 3H), 6.7 (s, IH), 7.1-7.12 (m, 2H), 7.95-8.05 (m, 2H); EMS 204.
Solution of 5-bromopentyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II (1400 mg, 3.97 mmol), A solution of (25)-N-(4-hydroxy-5-methoxy-2-nitrobenzoyl)pyrrohdine-2-carbox-aldehydediethylthioacetal of formula III (1590 mg, 3. 97 mmol) and K2CO3 (1640 mg, 11.898 mmol) in dry acetone (20 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purilied by column chromatography on silica' gel eluting with EtOAc-hexane (27:73) gave the pure (25)-N-[{4[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy}-5-methoxy-2°-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV. 1H NMR (CDCI3) 5 1.2-1.5 (m, 8H), 1.60-,
2.4 (m, 8H), 2.64 (s, 3H), 2.7-2.82 (m, 4H), 3.2-3.3 (m, 2H), 3.95 (s, 3H), 4.2 (m, 2H), 4.35-4.48 (t, 2H, J = 6.5 Hz), 4.62-4.75 (m, H), 4.85 (d, 1H, J = 4.2 Hz), 6.78 (s, 1H), 6.82 (s, 1H), 7.05-7.20 (m, 2H), 7.65 (s, IH), 7.95-8.1 (m, 2H); FABMS 939 (M+H)+.
(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (500 mg, 0.74 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (840 mg 3.72 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCO3 solution and then extracted with ethyl acetate (3x30 mL). The combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford the crude (25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy}-5-methoxy-2-aminobenzoyl]pyrrolidine-2-carbo xaldehyde diethyl thioacetal of formula V.
Solution of formula V (300 mg, 0.47 mmol), HgCh (280 mg, 1.03 mmol) and CaCO3 (110 mg, 1.10 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCO3 was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy-(llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-on e of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtOAc. 1HNMR (CDCI3) 6 1.6-2.2 (m, l0H), 2.65 (s, 3H), 3.6-3,8 (m, 2H), 3.95 (s, 1H), 4.1-4.2 (m, 2H) 4.45 (m, 2H), 6.84 (s, 1H), 6.86 (s, H), 7.1-7.22 (m, 2H), 7.65 (s, 1H), 7.68-7.71 (d, 1H, J = 4.4 Hz), 8.0-8.1 (m, 2H); FABMS: 631 (M+H)+.
Example 4
Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg 4.90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was fiirther purified by column chromatography on silica gel eluting with EtOAc-hexane (5:95) gave the pure 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II.
Solution of 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N- (4-hydroxy-5-
methoxy-2-nitrobenzoyl) pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472
mg, 3,69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for
48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave the pure (4R)-hydroxy-(25)-N-[{4-[6'-(4"-
fluorophenyl)-2'-methylpyrimidine-4'-yloxy] propoxy}-5-methoxy-2-nitrobenzoyl]
pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV.
(4R)-hydroxy-(25)-N- [ {4- [6' -(4" -fluorophenyl)-2' -methylpyrimidine-4' -y loxy] propoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal IV (500 mg, 0.78 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (873 mg 3.88 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCOs solution and then extracted with ethyl acetate (3x30 mL). The combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford crude (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy"lpropoxy}-5-methoxy-2-mtrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula V.
Solution of formula V (300 mg, 0.5 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCO3 was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy-(4R)-hydroxy-(l laS)-l,2,3,1 la-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtoAc-methanol (9:1).
Example 5 Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg 4.90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.7 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane
(5:95) gave the pure 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II.
Solution of 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyi ether of
formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N- (4-hydroxy-5-
methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472
mg, 3 69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for
48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave the pure (4R)-hydroxy-(25)-N-[{4-[6'-(4"-
fluorophenyl)-2'-methylpyrimidine-4'-yloxy] butoxy}-5-methoxy-2-nitrobenzoyl]
pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV.
(4R)-hydroxy-(25)-N-[ {4-[6' -(4' -fluorophenyl)-2' -methyIpyrimidine-4' -yloxy] butoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (500 mg, 0.78 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (873mg 3.88 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCOs solution and then extracted with ethyl acetate (3x30 mL). The combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford crude (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy}-5-methoxy-2-nitrobenzoyl] pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula V.
Solution of formula V (300 mg, 0.5 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCOs (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOa was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate was evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy-(4R)-hydroxy-(l laS)-l,2,3,1 la-tetrahydro-5H-pyrrolo[2,l,c][l,4]ben zodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtOAc-methanol (9:1).
Example 6
Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg, 4.90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by

TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (5:95) gave the pure .3-bromopropyl-6-(4-fluoro phenyl)-2-methyI-4-pyrimidyl ether of formula II.
Solution of 3-bromopropyl-'6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of
formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N-(4-hydroxy-5-
methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472
mg, 3.69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for
48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave pure (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-
2' -methylpyrimidine-4' -yloxy] pentoxy} -5-methoxy-2-nitrobenzoyl] pyrrolidine-2-
carboxaldehyde diethyl thioacetal of formula IV.
(4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]
pentoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of
formula IV (500 mg, 0.78 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O
(873 mg 3.88 mmol) was refluxed for 1.5 h. Reaction mixture was then carefully adjusted to
pH 8 with saturated NaHCOa solution and then extracted with ethyl acetate (3x30 mL).
Combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford
crude (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]
pentoxyl-5-methoxy-2-aminobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula V.
Solution of formula V (300 mg, 0.50 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOs was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]penToxy-(4R)-hydroxy-(l laS)-l,2,3,1 la-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-i-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and fiarther eluted with EtOAc-methanol (9:1).
Example 7
Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg, 4.90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (5;95) gave the pure3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II.
Solution of 3-bromopropyl-6-(4-fluorophenyl)-2-methyl-4-pyrimidyl ether of formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N-(4-hydroxy-5-methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472 mg, 3.69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (1:3) gave pure (4R)-hydroxy-(2 To a stirred solution of (4R)-hydroxy-(2-N-[(4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (660 mg, 1.00 mmol) in dichloromethane (10 mL) triethylamine (125 mg, 1.20 mmol) was added under N2 atmosphere at 0°C. After stirring for 5 min. acetylchloride (100 mg, 1.20 mmol) was added drop wise at same temperature and reaction mixture was allowed to stir at room temperature and reaction mixture was allowed to stir at room temperature for overnight and then poured into water, extracted with dichloromethane and dried over Na2SO4 and evaporated in vacuo to afforded the corresponding compound (4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4' -yloxy]propoxy} - 5 -methoxy-2-nitrobenzoyl] pyrrolidine-2-carboxaldehyde diethyl thioacetal.
(4R)-acetyloxy-(2y)-N-[ {4-[6' -(4 " -fluorophenyl)-2' -methylpyrimidine-4' -yloxy] propoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal (600 mg, 0.81 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (880 mg 3.90 mmol) was refluxed for 1.5 h. Reaction mixture was then carefully adjusted to pH 8 with
saturated NaHCOs solution and then extracted with ethyl acetate (3x30 mL). Combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford the crude (4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy}-5-methoxy-2-aminobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula V.
Solution of formula V (350 mg, 0.50 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOs was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]propoxy-(4R)-acetyloxy-(llaS)-l,2,3,1la-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtOAc-methanol (9:1).
Example 8
Solution of 6-(4-fluorophenyi)-2-methyl-4-pyridinol of fonnula I (1000 mg, 4 90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14.70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which was further purified by column chromatography on silica gel eluting with EtOAc-hexane (5:95) gave the pure3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II.
Solution of 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of
formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N-(4-hydroxy-5-
methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472
mg, 3.69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for
48 h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave pure (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-
2'-methylpyrimidine-4'-yloxy] butoxy}-5-methoxy-2-nitrobenzoyl] pyrrolidine-2-
carboxaldehyde diethyl thioacetal of formula IV.
To a stirred solution of (4R)-hydroxy-(2y)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula IV (674 mg, 1.00 mmol) in dichloromethane (10 mL) triethylamine (125 mg, 1.2 mmol) was added under N2 atmosphere at 0.°C. After stirring for 5 min. acetylchloride (100 mg, 1.20 mmol) was added drop wise at same temperature and reaction mixture was allowed to stir at room temperature for overnight and then poured into water, extracted with dichloromethane and dried over Na2SO4 and evaporated in vacuum to afforded the corresponding compound (4R)-acetyloxy-(25)-N-[{4-[6' -(4" -fluoropheny l)-2' -methylpyrimidine-4' -yloxy]butoxy } -5-methoxy-2-nitrobenzoyl] pyrroIidine-2-carboxaldehyde diethyl thioacetal.
(4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy] butoxy}-5-methoxy-2-nitrobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal (600 mg, 0.79 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (880 mg, 3.95 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCOa solution and then extracted with ethyl acetate (3x30 mL). Combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford crude (4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]butoxy}-5-methoxy-2-aminobenzoyl]pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula V.
Solution of formula V (360 mg, 0.50 mmol), HgCl2(300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3;1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCOs was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluoropheny l)-2' -methylpyrimidine-4' -y loxy ] butoxy-(4R)-acetyloxy-( llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and further eluted with EtOAc-methanol (9:1).
Example 9 Solution of 6-(4-fluorophenyl)-2-methyl-4-pyridinol of formula I (1000 mg, 4.90 mmol), 1, 3-dibromopropane (2475 mg, 12.25 mmol) and K2CO3 (2030 mg, 14,70 mmol) in dry acetone (40 mL) was refluxed for 48 h. After the completion of reaction as indicated by TLC, EtOAc-hexane (2:8), the reaction mixture was poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer gave the crude product, which
was further purified by column chromatography on silica gel eluting with EtOAc-hexane (5:95) gave the pure 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of formula II.
A solution of 3-bromopropyl-6-(4-fluoro phenyl)-2-methyl-4-pyrimidyl ether of
formula II (1200 mg, 3.69 mmol), A solution of (4R)-hydroxy-(25)-N-(4-hydroxy-5-
methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethylthioacetal of formula III (1472
mg, 3.69 mmol) and K2CO3 (1530 mg, 11.07 mmol) in dry acetone (20 mL) was refluxed for
48h. After the completion of reaction as indicated by TLC, EtOAc, the reaction mixture was
poured on to the water and then extracted with ethyl acetate. Evaporation of the organic layer
gave the crude product, which was further purified by column chromatography on silica gel
eluting with EtOAc-hexane (1:3) gave pure (4R)-hydroxy-(2S)-N-[{4-[6'-(4"-fluorophenyl)-
2'-methylpyrimidine-4'-yloxy] pentoxy}-5-methoxy-2-nitrobenzoyl] pyrrolidine-2-
carboxaldehyde diethyl thioacetal of formula IV.
To a stirred solution of (4R)-hydroxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-
methylpyriraidine-4'-yloxy]pentoxy}-5-methoxy-2-nitrobenzoyl] pyrrohdine-2-
carboxaldehyde diethyl thioacetal of formula IV (688 mg, 1 Ommol) in dichloromethane (l0mL) triethylamine (125 mg, 1.20 mmol) was added under N2 atmosphere at 0°C. After stirring for 5 min. acetyl chloride (100 mg, 1.20 mmol) was added drop wise at same temperature and reaction mixture was allowed to stir at room temperature overnight and then poured into water, extracted with dichloromethane and dried over Na2SO4 and evaporated in vacuum to afforded the corresponding compound (4R)-acetyloxy- (25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyriniidine-4'-yloxy]pentoxy}-5-methoxy-2-nitrobenzoyl] pyrrolidine-2-carboxaldehyde diethyl thioacetal.
(4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy] pentoxy}-5-methoxy-2-nitrobenzoyl]pyrroUdine-2-carboxaldehyde diethyl thioacetal (600 mg, 0,78 mmol) was dissolved in methanol (10 mL) and added SnCl2.2H2O (880 mg 3.90 mmol) was refluxed for 1.5 h. The reaction mixture was then carefully adjusted to pH 8 with saturated NaHCO3 solution and then extracted with ethyl acetate (3x30 mL). Combined organic phase was dried over Na2SO4 and evaporated under vacuum to afford crude (4R)-acetyloxy-(25)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy}-5-methoxy-2-aminobenzoyl]py rrolidine-2-carboxaidehyde diethyl thioacetal of formula V. '
Solution of formula V (365 mg, 0.50 mmol), HgCl2 (300 mg, 1.10 mmol) and CaCO3 (120 mg, 1.20 mmol) in CH3CN/H2O (3:1, 15 mL) was stirred at room temperature for 12 h until TLC (EtOAc), indicates complete loss of starting material. Then organic layer is,
evaporated in vacuum and the residue is diluted with EtOAc. To this saturated NaHCO3 was added slowly at room temperature and the mixture is filtered through celite and washed with ethyl acetate. The filtrate is evaporated in vacuum to get crude 7-methoxy-8-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy]pentoxy-(4R)-acetyloxy-( 11 aS)-1,2,3,11 a-tetrahydro-5H-pyrrolo[2,l,c][l,4]benzodiazepin-5-one of formula VI, which was further purified by column chromatography on silica gel eluting first with ethyl acetate to remove traces of mercuric salts and fiirther eluted with EtOAc-methanol (9:1). Biological Activity: In vitro biological activity studies were carried out at National Cancer Institute (USA).
Cytotoxicity: Compounds VIa and VIb were evaluated in vitro against sixty human tumour cells derived from nine cancer types (leukemia, non-small-cell lung, colon, CNS, melanoma, ovarian, prostate, and breast cancer). For each compound, dose response curves for each cell line were measured at a minimum of five concentrations at 10 fold dilutions. A protocol of 48 h continuous drug exposure was used and a sulforhodamine B (SRB) protein assay was used to estimate cell viability or growth. The concentration causing 50% cell growth inhibition (GI50), total cell growth inhibition (TGI 0% growth) and 50% cell death (LC50, -50% growth) compared with the control was calculated. The mean graph midpoint values of logioTGI and logioLC50 as well as logio GI50 for Via and VIb are listed in Table 1. As demonstrated by mean graph pattern, compound VIb exhibits an interesting profile of activity and selectivity for various cell lines. The mean graph mid point of logio TGI and logio LC50 showed similar pattern to the logio GI50 mean graph mid points.
Table 1. logio GI50 logio TGI and logic LC50 mean graphs midpoints(MG_MID) of in vitro cytotoxicity data for the compounds VIa and VIb against human tumour cell lines.
(Table Removed)
The comparison of the data of Table 2 reveals the importance of the alkane spacer. As the alkane spacer increased from 3-4 the cytotoxic activity has moderately enhanced. The 4 carbon sipacer of compound VIb confers a suitable fit in the minor groove of double helix DNA and shows slightly higher activity in this series of compounds VIa and VIb. Table 2. Log LC50 (concentration in mol/L causing 50% lethality) Values for Compounds VIa and VIb
(Table Removed)
Each cancer type represents the average of six to eight different cancer cell lines.






We claim:
Novel pyrrolo[2,l-c][l,4]benzodiazepine of formula VI wherein R is H , OH, OAc and n is 3 to 5;

(Formula Removed)
A process for the preparation of novel pyrrolo [2,l-c][l,4]benzodiazepine of formula VI wherein R is H, OH, Oac and n is 3 to 5:
(Formula Removed)
the process comprising reacting 6-4-(4-fluorophenyl)-2-methyl-4-pyrimidinol of formula 1
(Formula Removed)
with a dibromoalkane in an aprotic water miscible organic solvent in the presence of a
mild inorganic base upto refluxing temperature for a period upto 48 h, isolating n-bromoalkyl-6-(4-flurophenyl)-2-methy!-4-pyrimidinyl ether of formula II with (2S)-N-(4-hydroxy-5-methoxy-2-methoxy-2-nitrobenzoyl)pyrrolidine-2-carboxaldehyde diethyl thioacetal of formula III
in presence of a mild inorganic base in presence of aprotic water miscible organic solvent upto refluxing for a period of 48 h, isolating (2S))-N-[{4-[6"-(4'-fluorophenyl)-2' -methylpyrimidine-4' -yloxy]alkoxy} -5 -methoxy-2-nitrobenzoyl} pyrrolidine-2-carboxaldehyde diethyl thioacetal reducing the above said compound with SnCl2.2H2O in presence of organic solvent upto a reflux temperature, isolating the (2S)-N-[{4-[6'-(4"-fluorophenyl)-2'-methylpyrimidine-4'-yloxy] alkoxy}-5-methoxy-2-amonobenzoyl] pyrrolidine-2-carboxaldehyde diethyl thioacetal, reacting the above said compound with a deprotection agent to obtain the pyrrolo[2,l-c][l,4]benzodiazepines.
A process as claimed in claim 1-2 wherein the aprotic water miscible organic solvent is selected from the group consisting of acetone, THF and DMF.
3. A process as claimed in claims 1-3 wherein the mild inorganic base is selected from the group consisting of K2CO3, CsCO3 and BaCO3.
4. Novel pyrrolo[2,l-c][l,4]benzodiazepine and a process for the preparation of novel pyrrolo [2,l-c][l,4]benzodiazepine substantially as herein described with reference to the examples.

Documents:


Patent Number 242189
Indian Patent Application Number 747/DEL/2003
PG Journal Number 34/2010
Publication Date 20-Aug-2010
Grant Date 18-Aug-2010
Date of Filing 29-May-2003
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 KARNATI LAXMA REDDY INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD-500 007, INDIA
2 AHMED KAMAL INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD-500 007, INDIA
PCT International Classification Number A61K 31/55
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA