Patent ID: 6130336
Filing Date: 2000-10-10
Classification: A61P,C07D,Y02P

Abstract:
A process for preparing paclitaxel represented by the following formula 1: ##STR22## characterized in that (a) an oxazolidine derivative represented by the following formula 2 or its salt: ##STR23## in which X represents halogen, is coupled with a 7-trihaloacetyl-baccatin III represented by the following formula 3: ##STR24## in which R.sub.1 represents trihaloacetyl, in a solvent in the presence of a condensing agent to produce an oxazolidine substituent-containing taxane represented by the following formula 4: ##STR25## in which X and R.sub.1 are each as previously defined; (b) the oxazolidine ring is opened in a solvent in the presence of an acid, and the product thus obtained is reacted with benzoyl chloride in the presence of a base to produce a protected paclitaxel wherein the hydroxy group at 7-position is protected with trihaloacetyl group represented by the following formula 5: ##STR26## in which R.sub.1 is as previously defined; (c) then the protecting group at 7-position is removed by ammonia or a salt of ammonia with a weak acid in a solvent.