Napro Biotherapeutics, Inc.

Medhavi C Chander

James D McChesney

Jan J Zygmunt

Nicholas J Sisti

Xian Liang

Herbert R Brinkman

The present invention relates to a method of producing paclitaxel or a paclitaxel analog comprising the esterification of C-7, C-10 di-CBZ 10-deacetylbaccatin III with an N-carbamate protected, C-2-protected 3-phenyl isoserine side chain. The C-7, C-10 carbobenzyloxy groups are then replaced with hydrogen and an acyl group is substituted at the C-3&prime; nitrogen. The resulting compound is acylated at the C-10 hydroxyl position, and deprotected at the C-2&prime; position by replacing the hydroxyl protecting group with hydrogen to produce paclitaxel or a paclitaxel analog. The present invention also relates to alternative methods of acylating a 10-hydroxy paclitaxel analog. The first method comprises dissolving a 10-hydroxy paclitaxel analog in an acceptable ether solvent therefor to form a first solution at a first temperature. The first solution is then cooled to a second temperature, and an alkali base is added to form an intermediate compound having a metal alkoxide at the C-10 position thereof, after which an acylating ageht is then added. The second method comprises dissolving a 10-hydroxy paclitaxel analog in an acceptable ether solvent therefor. An alkali salt is added, and a trialkyl amine base or pyridine is next added, followed by the addition of an acylating agent. The present invention is additionally directed to a C-10 metal alkoxide chemical intermediate for use in producing paclitaxel or paclitaxel analogs.

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Boulder, CO, United States of America

Medhavi C Chander