Title of Invention

"A PROCESS FOR THE PREPARATION OF 14B-HYDROXY-1,14-CARBONATE-DEACETYLBACCATIN III"

Abstract The present invention relates to a process for the preparation of 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III, which comprise the following, steps: protection of the hydroxyls at the 7- and 10- positions of 10-deacetylbaccatin III, wherein R and R1 are trichloroacetyl, with trichloroacetyl chloride in methylene chloride in the presence of triethylamine and of catalytic amounts of N,N-dimethylaminopyridine; two-step oxidation to give the derivative oxidized to carbonyl at the 13-position and hydroxylated at the 14-position: in which the oxidation of the hydroxyl at the 13-position and the hydroxylation at the 14-position are effected with manganese dioxide or bismuth dioxide in a solvent selected from acetonitrile, acetone or ethyl acetate/methylene chloride mixtures; carbonation of the vicinal hydroxyls at the 1- and 14-position with phosgene in mehtylene chloride/toluene mixture in the presence of pyridine to give the 1, 14-carbonate derivative: reduction of the carbonyl at the 13-position with sodium borohydride in methanol: removal of the protective groups at the 7- and 10-position to give 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III.
Full Text The present invention relates to a process for the preparation of 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III
The present relates to a novel intermediates useful in the synthesis of 14ß-hydroxy-1,14-carbonate-deacetylbaccatin III derivatives, and to a process for the preparation thereof. The intermediates obtained with the process of the invention can be used in the preparation of novel taxan derivatives with antitumor activity.
Taxanes are one of the most important classes of antitumor agents developed in recent years. Paclitaxel is a complex diterpene from the bark of taxus brevifolia and is considered a "lead compound" for cancer therapy. Extensive research is at present being carried out for taxan derivatives having higher pharmacological activity and improved pharmacokinetic profile. A particular approach relates to the baccatin II derivatives variously modified with respect to the basic structure. Examples f said compounds are the 14ß-hydroxy baccatin III derivatives disclosed in US 5,705, 508, WO 97/43291, WO 96/36622. At present 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III derivatives are prepared starting from the 14ß-hydroxy-deacetylbaccatin III precursor, which is a natural compound obtainable in small amounts by extraction of leaves of Taxus wallichiana, as disclosed in EP 559, 019. There is strong need for novel intermediates or alternative processes to those commonly used, which allow to prepare 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III derivatives simply and effectively.
It has now been found that 146-hydroxy-l,14-carbonate-deacetylbaccatin III can be prepared by means of a process using 10-deacetylbaccatin III as starting compound which, contrary to 14ß-hydroxy-baccatin III, can be easily isolated in large amounts form Taxus baccata leaves.
Therefore, the present invention provides a process for the preparation of
14ß-hydroxy-l,14-carbonate-deacetylbaccatin III comprising the following steps:
1. protection of the hydroxy groups at the positions 7 and 10 of 10 deacetylb accatin III:
(Figure Removed)
wherein R and R1 are selected from hydrogen, C1-C10 alkyl or aryl, C1-C10 alkyl- or aryl-carbonyl, trichloroacetyl, C1-C4 trialkylsilyl; preferably, when R and R1 are the same, they are trichloroacetyl, whereas when they are different, preferably R is trichloroacetyl and R1 is acetyl, or R is triethyl or trimethylsilyl and Ri is acetyl; 2 two-step oxidation to give the derivative oxidised at the 13- position and hydroxylated at the 14- position:
(Figure Removed)
3. carbonation of the vicinal hydroxyls at the 1- and 14- positions to give the 1,14-carbonate derivative:
(Figure Removed)
4. reduction of the carbonyl at the 13- position:
(Figure Removed)
5. removal of the protective groups at the 7- and 10- positions:
(Figure Removed)
The procedures for the protection of the 7- and 10- hydroxyls are described by Holton et al., Tetrahedron Letters 39, (1998) 2883-2886. The selective protection of the hydroxyls of the starting compound deacetylbaccatin III is possible due to their different reactivity. In particular, the reactivity towards acylating, alkylating or silylating agents has been found to vary in the order C(7)-OH>C(10)-OH>C(13)-OH>C(1)-OH, therefore the groups at 7- and 10- can be selectively protected while keeping the hydroxyls at 1- and 13- free.
Furthermore, by changing the reaction conditions, it is possible to reverse the reactivity order of the hydroxyls at 7- and 10- thus allowing the differential substitution thereof. Examples of reactants and reaction conditions usable in the protection of the hydroxyls at 10- and 7- are reported in the above cited publication.
The oxidation step of the hydroxyl at the 13- position is achieved with manganese dioxide or bismuth dioxide in a solvent selected from acetonitrile, acetone or ethyl acetate/methylene chloride 9:1 mixtures, under vigorous stirring, preferably with manganese dioxide in acetonitrile or acetone. The reaction proceeds quickly to give the oxidised derivative at the 13- position, which can be recovered from the reaction medium, whereas a longer reaction yields the 13- oxidised and 14- hydroxylated derivative.
The subsequent carbonation step of the hydroxyls at the 1- and 14-
positions is usually effected with phosgene or triphosgene in a methylene
chloride/toluene mixtuie in the presence of pyridine. Subsequently, the
resulting 1,14-carbonate derivative can be easily reduced at the 13- position to
give the corresponding 13-hydroxy derivative. Said reduction takes place
regioselectively on the carbonyl at 13- while the carbonyl at 9- remains
unchanged, and stereoselectively, affording almost exclusively the 13-α
isomer. This reaction is usually carried out with sodium borohydride in
methanol and provides high yields. The last step consists in deprotecting the
hydroxyls at the 7- and 10- positions to give the final product 14P-hydroxy-
1,14-carbonate deacetylbaccatin III. The conditions and the reactants which can
be used in the selective deprotection of the hydroxyls at 7- and 10- are
described in Zheng et al., Tetrahedron Lett., 1995, 36, 2001, and in Datta et al,
J. Org. Chem., 1995, 60, 761. The resulting final product is an extremely useful
intermediate for the synthesis of a variety of taxan derivatives. As mentioned
above, said intermediate was prepared until now starting from 14ß-hydroxy
baccatin III extracted from the leaves of Taxus wallichiana in low yields. The process of the present invention allows to prepare the same intermediate in high yields starting from a compound available in large amounts. Examples of compounds with antitumor activity which can be prepared starting from 14ß-hydroxy-l,14-carbonate deacetylbaccatin III are reported in US 5,705,508, WO 97/43291, WO 96/36622.
According to a preferred embodiment of the process of the invention,
deacetylbaccatin III is reacted with trichloroacetyl chloride in methylene
chloride in the presence of triethylamine and using N,N-dimethylaminopyridine
(DMAP) in catalytic amounts. The use of trichloroacetate as protecting group
proved to be very advantageous in the oxidation, carbonation and reduction
steps according to the process of the invention. In particular, the 7,10-bis-
trichloroacetate derivative, which is obtained in quantitative yields from the
starting compound, after oxidation and carbonation is easily reduced at the 13-
position with simultaneous deprotection of the trichloroacetic groups to give
14P-hydroxy-l,14-carbonate-deacetylbaccatin III. The use of DMAP in
catalytic amounts provides definite advantages from the industrial and
environmental point of views, when considering that until now the acylations
of this substrate were carried out in pyridine with consequent discharge
problems of the residual solvent.
The following intermediates obtained according to the preferred embodiment described above are part of the present invention:
(Figure Removed)
The following examples illustrate the invention in greater detail.
Statement of invention
In accordance with the present invention it relates to a A process for the preparation of 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III, which comprise the following, steps: protection of the hydroxyls at the 7- and 10- positions of 10-deacetylbaccatin III:
wherein R and R1 are irichloroacetyl, with trichloroacetyl chloride in methylene chloride in the presence of triethylamine and of catalytic amounts of N,N-dimethy laminopyridine;
two-step oxidation to give the derivative oxidized to carbonyl at the 13-position and hydroxylated at the 14-position:
(Figure Removed)
in which the oxidation of the hydroxyl at the 13-position and the hydroxylation at the 14-position are effected with manganese dioxide or bismuth dioxide in a solvent selected from acetonitrile, acetone or ethyl acetate/methylene chloride mixtures;
carbonation of the vicinal hydroxyls at the 1- and 14-position with phosgene in mehtylene chloride /toluene mixture in the presence of pyridine to give the 1, 14-carbonate derivative:
reduction of the carbonyl at the 13-position with sodium borohydride in methanol:
removal of the protective groups at the 7- and 10-position to give 14ß-hydroxy-l,14-carbonate-deacetylbaccatin III.
Example I
Preparation of 7,10-bistrichloroacetyl-10-deacetylbaccatin III.
4.77 ml of trichloroacetic anhydride (42.32 mmol) is added by drops to a solution of 10 g of 10-deacetylbaccatin 111(18.4 mmol) in 125 ml of dry methylene chloride and 42 ml of pyridine. The reaction mixture is kept under stirring for three hours or anyway until completion of the reaction, checking by TLC on silica gel using as eluent an n-hexane/ethyl acetate 1:1 mixture. After completion of the reaction, 5 ml of methanol are added to destroy the excess of trichloroacetic anhydride, then water is added. The organic phase is thoroughly washed with acidic water (HCL) to remove pyridine, whereas the remaining organic phase is dried over MgSO4 and concertrated to dryness under vacuum, to obtain a pale yellow solid (17 g) which is crystallized from chloroform: [α] D -34° (CH2CL2 C5.8)IR (KBr) 3517, 1771, 1728, 1240, 981, 819, 787, 675 CM-1;
1H-NMR (200MH): δ 8.11 (Bz C), 7.46 (Bz, BB'), 6.50 (s, H-10), 5.72 (m, H-7 H-29, 5.02 (d, J=8 Hz, H-5), 4.95 8m, H-13), 4.37 (d, J = 8 Hz, H-20a), 4.18 (d, J = 8 Hz, H-20b), 4.02 (d, J = 6 Hz, H-3), 2.32 (s, 4-Ac), 2..22 (s, H-18), 1.91 (s, H-19), 1.25 and 1.11 (s, H-16, H-17), 1.94 (m, H 14a), 1.89 (m, H14(5).
Second alternative:
10-deacetilbaccatin III (10 g, 18.38 mmol) is suspended in CH2Cl2 (120 ml), added with DMAP (220 mg, 1.4 mmol, 0.1 eqv.) and cooled to 0°C on ice bath. Et3N (10.26 ml, 73.6 mmol, 4 eqv.) and immediately after, Cl3CCOCl (4.12 ml, 36.8 mmol, 2 eqv.) are added under nitrogen stream in 5 min, keeping the temperature under 10°C. After completion of the addition, the mixture is left under stirring on ice bath for 15 min, then the bath is removed
and the reaction stirred at room temperature for 1 h. After 1 h the reaction is checked by TLC (AcOEt 2/n-hexane 3, Rf 10-DAB III = 0.05, Rf 7,10-bistrichloroacetyl -10-DAB III = 0,26) and added with C13CCOC1 (1 ml, 0.5 eqv.). Stirring is continued at r.t. for 10 min, then the reaction is poured into a beaker containing 160 g of triturated ice and left under stirring until equilibrium at r.t. (about lh). The aqueous phase is then separated and extracted with CH2Cl2 (3 x 40 ml). The combined organic phases are washed with IN HC1 (20 ml), then with a NaHCO3 saturated solution (20 ml), dried over Na2SO4 and the solvent is evaporated off. Crude weight: 16.5 g. After crystallisation from chloroform, the IR, 1H-NMR and [α]D spectra are consistent with those of the compound obtained using pyridine and trichloroacetic anhydride. Example II
Oxidation at 13- and hydroxylation at 14- of 7.10-bistrichloroacetate 10-deacetvlbaccatin III.
30 g of activated MnO2 are added to a solution of 10-deacetylbaccatin III 7,10-bistrichloroacetate (3 g) in acetonitrile (40 ml), stirring the suspension with magnetic stirrer at room temperature and monitoring the progress of the reaction by TLC (petroleum ether-ethyl acetate 5:5; Rf of the .starting material about 0.31). After about one hour, the formation of the 13-dehydroderivative is completed (TLC analysis, Rf of the 13-dehydroderivative about 0.50). Stirring is then continued for about 72 hours, during which time the 13-dehydroderivative is slowly oxidised to the corresponding 14ß-hydroxy derivative (Rf about 0.36). The reaction mixture is filtered through Celite, and the cake is repeatedly washed with ethyl acetate. The solvent is evaporated off and the residue is purified by column chromatography on silica gel (100 ml, eluent petroleum ether-ethyl acetate 7:3) to obtain 170 mg of the 13-dehydroderivative and 2.38 g of the 14ß-hydroxy- 13-dehydroderivative.
(dd, J = 10.6 Hz, H-7), 4.33 (d, J = 8.0 Hz, H-20a), 4.12 (d, J = 8.0 Hz, H-20b), 3.91, (d, J = 6.9 Hz,H-3), 2.96 (d, J = 20 Hz, H-14a), 2.65 (d, J = 20 Hz, H-20b), 2.50 (m, H-6a), 2.23 (s, OAc), 2.19 (s, OAc + H-18), 1.67, 1.28, 1.19 (s, H-16, H-17 and H-19), 0.19 (m, TES).
13-Dehydro-14P-hydroxy-10-deacetylbaccatin IH, 7,10-bis trichloroacetate: white powder, m.p. 153°C [α]D25 + 20 (CH2C12, C 0.75) IR (KBr) 3431, 1723, 1692, 1371, 1269, 1242, 1223, 1096 cm-1; 1H-NMR (500MH CDC13): δ 8.06 (Bz AA'), 7.60 (Bz, C), 7.48 (Bz, BB'), 6.51 (s, H-10), 5.88 (d, J = 6.9 Hz, H-2), 4.90 (d, J = 8.2 Hz, H-5), 4.47 (dd, J = 10.6 7 Hz, H-7), 4.30 (d, J = 8 Hz, H-20a), 4.28 (d, J = 8.2 Hz, H-20b), 4.13 (br d, J = 2 Hz, H-14), 3.84 (d, J = 6.9 Hz, H-3), 3.69 (br d, J = 2 Hz, 14-OH), 3.62 (s, 1-OH), 2.52 (m, H-6a), 2.24 (s, OAc), 2.21 (s, OAc), 2.11 (s, H-18), 1.92 (m, H-60), 1.74, 1.56, 1.28 (s, -h-16, H-17 and H-19), 0.94 (m, TES), 0.59 (m, TES). HRNS: 714.3092 (calculated for C37H50012Si 714.3092). Example IV Oxidation/hydroxylation of 7-triethylsilylbacoatin III
10 g of activated MnO2 are added to a solution of 7-triethylsilylbaccatin III (1.0 g) in acetonitrile (10 ml), with stirring at room temperature and monitoring the progress of the reaction by TLC (petroleum ether-ethyl acetate 6:4; Rf of the starting material about 0.25). After about two hours, the formation of the 13-dehydroderivative is completed (TLC analysis, Rf of the 13-dehydroderivative about 0.45). Stirring is then continued for about 188 houTS, during which time further MnO2 (10 g) is added. The 13-dehydroderivative is slowly oxidised to the corresponding 14p-hydroxy derivative (Rf about 0.38). The reaction mixture is filtered through Celite, and the cake is washed with ethyl acetate. The solvent is evaporated off and the residue is purified by column chromatography on silica gel (40 ml, eluent petroleum ether-ethyl acetate 7:3) to obtain 126 mg of the 13-
(dd, J = 10.6 Hz, H-7), 4.33 (d, J = 8.0 Hz, H-20a), 4.12 (d, J = 8.0 Hz, H-20b), 3.91, (d, J = 6.9 Hz,H-3), 2.96 (d, J = 20 Hz, H-14a), 2.65 (d, J = 20 Hz, H-20b), 2.50 (m, H-6a), 2.23 (s, OAc), 2.19 (s, OAc + H-18), 1.67, 1.28, 1.19 (s, H-16, H-17 and H-19), 0.19 (m, TES).
13-Dehydro-14ß-hychoxy-10-deacetylbaccatin III, 7,10-bis trichloroacetate: white powder, m.p. 153°C [α]D25 + 20 (CH2C12, C 0.75) IR (KBr) 3431, 1723, 1692, 1371, 1269, 1242, 1223, 1096 cm-1; 1H-NMR (500MH CDC13): δ 8.06 (Bz AA'), 7.60 (Bz, C), 7.48 (Bz, BB'), 6.51 (s, H-10), 5.88 (d, J = 6.9 Hz, H-2), 4.90 (d, J = 8.2 Hz, H-5), 4.47 (dd, J = 10.6 7 Hz, H-7), 4.30 (d, J = 8 Hz, H-20a), 4.28 (d, J = 8.2 Hz, H-20b), 4.13 (br d, J - 2 Hz, H-14), 3.84 (d, J = 6.9 Hz, H-3), 3.69 (br d, J = 2 Hz, 14-OH), 3.62 (s, 1-OH), 2.52 (m, H-6a), 2.24 (s, OAc), 2.21 (s, OAc), 2.11 (s, H-18), 1.92 (m, H-6ß), 1.74, 1.56, 1.28 (s, -h-16, H-17 and H-19), 0.94 (m, TES), 0.59 (m, TES). HRNS: 714.3092 (calculated for C37H50012Si 714.3092). Example IV Oxidation/hydroxylation of 7-triethylsilylbaccatin III
10 g of activated Mn02 are added to a solution of 7-triethylsilylbaccatin III (1.0 g) in acetonitrile (10 ml), with stirring at room temperature and monitoring the progress of the reaction by TLC (petroleum ether-ethyl acetate 6:4; Rf of the starting material about 0.25). After about two hours, the formation of the 13-dehydroderivative is completed (TLC analysis, Rf of the 13-dehydroderivative about 0.45). Stirring is then continued for about 188 hours, during which time further MnO2 (10 g) is added. The 13-dehydroderivative is slowly oxidised to the corresponding 14ß-hydroxy derivative (Rf about 0.38). The reaction mixture is filtered through Celite, and the cake is washed with ethyl acetate. The solvent is evaporated off and the residue is purified by column chromatography on silica gel (40 ml, eluent petroleum ether-ethyl acetate 7:3) to obtain 126 mg of the 13-
which is purified on a small silica gel column (about 5 ml, eluent hexane/ethyl acetate 8:2) to obtain 118 mg (92%) of the carbonate. When the reaction is carried out with triethylamine as base without the reverse addition, mixture of 1,14-carbonate and 2-debenzoyl-l,2-carbonate-14 benzoate (about 1 : 15) is obtained.
13-Dehydro-14ß-hydroxy-7-triethylsilylbaccatin III 1,14-carbonate, white powder, m.p, 153°C [α]D25 + 23 (CH2C12, C 0.75) IR (KBr) No. of band OH 1834, 1734, 1709, 1373, 1242, 1225, 1088, 1057 cm-1; 1H-NMR (200MH CDC13): 5 7.99 (Bz AA'), 7.60 (Bz, C), 7.48 (Bz, BB'), 6.51 (s, H-10), 6.12 (d, J = 6.9 Hz, H-2), 4.90 (d, J = 8.2 Hz, H-5), 4.78 (s, H-14), 4.44 (dd, J = 10.7 Hz, H-7), 4.34 (d, J = 8 Hz, H-20a), 4.19 (d, J = 8.2 Hz, H-20b), 3.80 (d, J = 6.9 Hz, H-3), 2.50 (m, H-6α), 2.23 (s, OAc), 2.22 (s, OAc), 2.19 (s, H-18), 1.92 (m, H-6ß), 1.72,1.39,1.26 (s, -H-16, H-17 and H-19), 0.90 (m, TES), 0.56 (m, TES). HRNS: 740.2851 (calculated for C38H48O13Si 740.2864). 13-Dehydro-14ß-hydroxybaccatin III 1,14-carbonate, white powder 240°C [α]D25 - 2.5 (CH2C12, C 0.4) IR (KBr) 3539, 1831, 1736, 1240, 1088, 1068, 1057, 1024 cm-1; 1H-NMR (200MH CDC13): δ 7.98 (Bz AA'), 7.61 (Bz, C), 7.50 (Bz, BB'), 6.39 (s, H-10), 6.14 (d, J = 6.9 Hz, H-2), 4.98 (d, J = 8.2 Hz, H-5), 4.80 (s, H-14), 4.43 (dd, J = 10.7 Hz, H-7), 4.35 (d, J = 8 Hz, H-20a), 4.24 (d, J = 8.2 Hz, H-20b), 3.80 (d, J = 6.9 Hz, H-3), 2.50 (m, H-6α), 2.30 (s, OAc), 2.20 (s, OAc), 2.15 (s, H-18), 1.90 (m, H-6ß), 1.74, 1.34, 1.25 (s, H-16, H-17 and H-19), HRMS: 626.2005 (calculated for C33H34O1 626.1999). Example VI Preparation of 1.14-carbonate-7-O-triethylsilyl baccatin III
An excess of NaBH4 (about 20 mg) is added in small portions to a solution of 13-dehydro-14ß-hydroxy-7-triethylsilylbaccatin III 1,14-carbonate (50 mg) in methanol (5 ml). After 30 min., the reaction mixture is added with saturated NH4Cl, extracted with ethyl acetate, washed with brine, dried over
Na2SO4 and the solvent is removed, to give a residue which is purified by column chromatography in silica gel (about 5 ml, elution with hexane-ethyl acetate 8:2) to obtain 35 mg of the 13α-hydroxy derivative and 9 mg of the 13ß-hydroxy derivative.
14ß-Hydroxy-7-triethylsilylbaccatin III 1,14-carbonate [α]D25 -35 (CH2C12, C 0.60) IR (KBr) 3054, 1819, 1736, 1603, 1371, 1261, 1238, 1090, 1069, cm-1; 1H-NMR (200MH CDC13): δ 8.06 (Bz AA'), 7.65 (Bz, C), 7.50 (Bz, BB'), 6.47 (s, H-10), 6.12 (d, J = 6.9 Hz, H-2), 5.05 (br d, J = 5.5 Hz, H-13), 4.98 (br d, J = 9 Hz, H-5), 4.83 (d, J = 5 Hz, H-14), 4.50 (dd, J = 10.7 Hz, H-7), 4.34 (d, J = 8 Hz, H-20a), 4.23 (d, J = 8 Hz, H-20b), 3.75 (d, J = 6.9 Hz, H-3), 2.56 (m, H-6α), 2.34 (s, OAc), 2.22 (s, OAc), 1.78 (m, H-6ß), 1.35 (s, H-18), 1.75, 1.18, 0.95 (s, -H-16, H-17 and H-19), 0.90 (m, TES), 0.62 (m, TES). 14P-Hydroxy-7-triethylsilyl-13-epibaccatin III 1,14-carbonate, amorphous [α] D25 - 13 (CH2C12, C 0.60) IR (KBr) 3630, 1825, 1734, 1603, 1375, 1262, 1091, 1071, 1049 cm-1; 1H-NMR (200MH CDC13): δ 8.01 (Bz AA'), 7.63 (Bz, C), 7.48 (Bz, BB'), 6.44 (s, H-10), 6.12 (d, J = 7.2 Hz, H-2), 4.90 (br d, J = 9 Hz, H-5), 4.81 (d, J = 8 Hz, H-14), 4.48 (br, J = 8, H-13), 4.50 (dd, J = 10, 7 Hz, H-7), 4.41 (d, J = 8 Hz, H-20a), 4.31 (d, J = 8 Hz, H-20b), 3.68 (d, J = 7.2 Hz, H-3), 2.60 (m, H-6a), 2.32 (s, OAc), 2.26 (s, H-18), 2.21 (s, OAc), 1.80 (m, H-6p), 1.72,1.43,1.27 (s, -H-16, H-17 and H-19), 0.93 (m, TES), 0.61 (m, TES).
Example VII
Preparation of 13-dehvdro-14ß-hvdroxv-7,10-bistrichloroacetvl-baccatin III 1.14-carbonate.
A solution of 13-dehydro-14ß-hydroxy-7,10-bistrichloroacetyl-baccatin III (200 mg) in CH2C12 (2 ml) and pyridine (1.12 ml, 20 equiv.) is added in 5 min with a solution of phosgene (20% in toluene, 3.6 ml, 20 equiv.) in CH2Cl2 (2 ml). The mixture is stirred at r.t. for 1 h, then the excess of phosgene is
neutralised with a NaHCO3 saturated solution (3 ml). The mixture is extracted with CH2Cl2, the organic phase is washed with a NaHCO3 saturated solution, then with a NaCl saturated solution and dried over Na2SO4. After removal of the solvent, the residue is purified by chromatography on a silica gel column (eluent hexane/AcOEt 9:1) to obtain 175 mg (89%) of the carbonate. 13-Dehydro-14ß-hydroxy-7,10-bistrichloroacetyl-baccatin III 1,14-carbonate, amorphous white solid. IR (KBr) 1834, 1771, 1735, 1709, 1232, 1103, 1010, 854 cm-1.
1H NMR (200 MHz, CDC13): δ = 8.03 (Bz AA'), 7.60 (Bz, C), 7.50 (Bz, BB'), 6.52 (s, H-10), 5.92 (d, J - 6.7 Hz, H-2), 5.70 (br t, J = 8.0 Hz, H-7), 4.95 (br d, J = 8.2 Hz, H-20b), 4.77 (s, H-14), 4.02 (d, J = 6.7 Hz, H-3), 2.71 (m, H-6), 2.29 (s, OAc), 1.96 (s, H-18), 1.27 - 1.01 (m, H-16, H-17, H-19). Example VIII Preparation of 14ß-hydroxy-10-deacetylbaccatm III 1.14-carbonate.
A solution of 13-dehydro-14ß-hydroxy-7,10-bistrichloroacetyl-baccatin III 1,14-carbonate (500 mg) in MeOH (8 ml) is cooled to 0°C on ice bath and added with solid NaBH4 (44 mg) in 5 min. The mixture is stirred at r.t. for 1 h, then cooled to 0°C. Acetone is added (2 ml) in 5 min, the mixture is concentrated, then added with AcOEt (10 ml) and filtered through Celite. The clear solution is washed with a NaCl saturated solution and dried over Na2SO4. The solvent is evaporated off to give a residue (4.5:1 mixture of C13 epimers) which is purified by chromatography on a silica gel column (eluent hexane/AcOEt 1:1) to obtain 251 mg of the 13ß epimer and 55 mg of the 13a epimer (88% total) of the deprotected carbonate.
13a-14P-hydroxy-10-deacetylbaccatin III 1,14-carbonate. amorphous white solid. IR (KBr): 3520 (OH), 1834,1709,1232,1103,1010, 854 cm-1. 1H NMR (200 MHz, CDC13): δ = 8.03 (Bz AA'), 7.60 (Bz, C), 7.50 (Bz, BB'), 6.27 (s, H-10), 5.92 (d, J = 6.7 Hz, H-2), 4.95 (br d, J = 8.2 Hz, H-20b), 4.85
(m, H-13), 4.77 (s, H-14), 4.42 (br t, J = 8.0 Hz, H-7), 4.02 (d, J = 6.7 Hz, H-
3), 2.71 (m, H-6), 2.29 (s, OAc), 1.96 (s, H-18), 1.27 - 1.01 (m, H-16, H-17, H-
19).
13a-14ß-hydroxy-10-deacetylbaccatin III 1,14-carbonate, amorphous white
solid. IR (KBr): 3520 (OH), 1834,1709,1232,1103,1010, 854 cm-1.
1H NMR (200 MHz, CDC13): δ = 8.03 (Bz AA'), 7.60 (Bz, C), 7.50 (Bz, BB'),
6.27 (s, H-10), 5.92 (d, J = 6.7 Hz, H-2), 4.95 (br d, J = 8.2 Hz, H-20b), 4.80
(m, H-13), 4.77 (s, H-14), 4.42 (br t, J = 8.0 Hz, H-7), 4.02 (d, J = 6.7 Hz, H-
3), 2.71 (m, H-6), 2.29 (s, OAc), 1.96 (s, H-18), 1.27-1.01 (m, H-16, H-17, H-
19).






We claim:
1. A process for the preparation of 14ß-hydroxy-l ,14-carbonate-deacetylbaccatin III, which comprise the following, steps:
a. protection of the hydroxyls at the 7- and 10- positions of 10-
dcacetylbaccatin III:
(Figure Removed)
wherein R and R1 are trichloroacctyl, with trichloroacetyl chloride in methylene chloride in the presence of triethylamine and of catalytic amounts of N,N-dimethylaminopyridine;
b. two-step oxidation to give the derivative oxidized to carbonyl at the 13-
position and hydroxylated at the 14-position:
(Figure Removed)
in which the oxidation of the hydroxyl at the 13-position and the hydroxylation at the 14-position are effected with manganese dioxide or bismuth dioxide in a solvent selected from acetonitrile, acetone or ethyl acetate/methylene chloride mixtures;
c. carbonation of the vicinal hydroxyls at the 1- and 14-position with
phosgene in mehtylene chloride/toluene mixture in the presence of
pyridine to give the 1, 14-carbonate derivative:
(Figure Removed)
d. reduction of the carbonyl at the 13-position with sodium borohydride in
methanol:
(Figure Removed)
e. removal of the protective groups at the 7- and 10-position to give 14ß-
hydroxy-1,14-carbonate-deacetylbaccatin III.
2. The following reaction intermediate:
13-dehydro-14ß-hydroxy-7,10-bistrichloroacetyl-baccatin III 1,14-carbonate, as obtained in step b) as claimed in claim 1.
3. A process for the preparation of 14ß-hydroxy-1,14-carbonate-dcacetylbaccatin III substantially as herein described with reference to the foregoing description , examples, tables and the accompanying drawings.

Documents:

121-delnp-2003-abstract.pdf

121-delnp-2003-assignment.pdf

121-delnp-2003-claims.pdf

121-delnp-2003-complete specification(as files).pdf

121-delnp-2003-complete specification(granted).pdf

121-DELNP-2003-Correspondence-Others-(07-09-2009).pdf

121-delnp-2003-correspondence-others.pdf

121-delnp-2003-correspondence-po.pdf

121-delnp-2003-description (complete).pdf

121-delnp-2003-form-1.pdf

121-delnp-2003-form-13-(07-09-2009).pdf

121-delnp-2003-form-13.pdf

121-delnp-2003-form-18.pdf

121-delnp-2003-form-2.pdf

121-delnp-2003-form-3.pdf

121-delnp-2003-form-5.pdf

121-delnp-2003-gpa.pdf

121-delnp-2003-pct-210.pdf

121-delnp-2003-pct-304.pdf

121-delnp-2003-pct-409.pdf

121-delnp-2003-pct-416.pdf

121-delnp-2003-petition-137.pdf

121-delnp-2003-petition-138.pdf


Patent Number 243654
Indian Patent Application Number 121/DELNP/2003
PG Journal Number 45/2010
Publication Date 05-Nov-2010
Grant Date 28-Oct-2010
Date of Filing 03-Feb-2003
Name of Patentee INDENA S.P.A
Applicant Address VIALE ORTLES, 12, I-20139 MILANO, ITALY
Inventors:
# Inventor's Name Inventor's Address
1 PONTIROLI, ALESSANDRO VIALE ORTLES, 12, I-20139 MILANO, ITALY
2 BOMBARDELLI, EZIO VIA VAL DI SOLE, 22-I-20141 MILANO, ITALY
PCT International Classification Number C07D 305/14
PCT International Application Number PCT/EP2001/08730
PCT International Filing date 2001-07-27
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI2000A001869 2000-08-10 Italy