The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1998
Filed:
Sep. 25, 1996
Nicholas J Sisti, Jeffersonville, PA (US);
Charles S Swindell, Merion, PA (US);
Other;
Abstract
A method for producing paclitaxel is accomplished by first esterifying C-7-CBZ baccatin III with a C3'-N-CBZ-C2'-O-protected (2R, 3S)-3-phenylisoserine side chain to form a first intermediate. Next, the carbobenzyloxy groups at C-7 and at the C3' nitrogen site of the first intermediate are respectively replaced with hydrogen and PhCO to produce a second intermediate that is next deprotected at C2' by replacing the protecting group with hydrogen. The C2' protecting group is a benzyl-type protecting group, preferably benzyloxymethyl or benzyl. Excess amounts, such as six equivalents, of the side chain are preferably employed. DMAP and a dialkylcarbodiimide are also preferably used during esterification. Various preferred reaction temperatures, times, and purification steps are disclosed.