Patent ID: 7247738

Claim:
A process for preparation of taxanes of formula 10: wherein R is phenyl or tertiary butoxy and R 1 is hydrogen, acetyl or chloroacetyl, wherein the process comprises the steps of: i) reacting compound of formula 6, wherein R1 is hydrogen, acetyl or chloroacetyl with (4S,5R)-3-[(2′-substituted or unsubstituted-2′-trialkylsilyl) ethoxy-carbonyl]-4-phenyl-2-mono or di-substituted-1,3-oxazolidine-5-carboxylic acid of formula 1, wherein R 2 is hydrogen or phenyl, R 3 is alkyl (C 1 to C 4 ) or p-methoxy phenyl and R 4 is hydrogen or alkyl (C 1 to C 4 ) in the presence of 4-dimethylaminopyridine, dicyclohexylcarbodiimide (DCC) and an aromatic hydrocarbon solvent to give compound of formula 7, wherein R 1 is hydrogen, acetyl or chloroacetyl, R 2 is hydrogen or phenyl, R 3 is alkyl (C 1 to C 4 ) or p-methoxy phenyl and R 4 is hydrogen or alkyl (C 1 to C 4 ); ii) reacting compound of formula 7 with a tetra alkyl ammonium halide in the presence of a haloalkane solvent to give compound of formula 8, wherein R 1 is hydrogen, acetyl or chloroacetyl; iii) reacting the solution of compound of formula 8 in the haloalkane solvent with an acid chloride or acid anhydride in the presence of an aqueous solution of a base to give compound of formula 9, wherein R is phenyl or tertiary butoxy and R 1 is hydrogen; acetyl or chloroacetyl; and iv) treating the compound of formula 9 with aqueous ammonia in the presence of pyridine at a temperature of between −20° to +40° C. to give taxane compound of formula 10.