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. 26, 1998
Filed:
Nov. 01, 1996
Applicant:
Inventors:
Ferdinand Hagedorn, Leverkusen, DE;
Helmut Fiege, Leverkusen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560 17 ;
Abstract
(2RS,3RS)-3-(2'-aminophenylthio)-2-hydroxy-3-(4'-methoxyphenyl)-propionic acid methyl ester, an important precursor for the preparation of the pharmaceutical active substance diltiazem, is obtained in a particularly high stereoselectivity and yield by addition of o-aminothiophenol onto 3-(4'-methoxyphenyl)-glycidic acid methyl ester if the reaction is carried out in the presence of alkali metal salts of weak acids in the presence of catalytic amounts of iron compounds.