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:
Sep. 15, 1998
Filed:
Apr. 22, 1997
Woo-Baeg Choi, North Brunswick, NJ (US);
Hywyn R Churchill, Radford, VA (US);
Joseph E Lynch, Plainfield, NJ (US);
Paul J Reider, Westfield, NJ (US);
Ralph P Volante, Cranberry, NJ (US);
Merck & Co., Inc., Rahway, NJ (US);
Abstract
A process for the preparation of Phosphodiesterase IV inhibitors is described. The process consists of eight chemical steps involving five isolations to prepare the title compound from readily available isovanillin in 35% overall yield (Scheme 1). The process is highlighted by: a) a highly diastereoselective Michael addition of phenyllithium using (1R, 2S) cis-aminoindanol as a chiral auxiliary, b) highly crystalline intermediates providing for efficient purifications, c) crystallization of the final compound as its CSA salt for excellent enantiomeric purity.