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. 10, 1994
Filed:
Jul. 28, 1992
Applicant:
Inventor:
Joseph Auerbach, Brooklyn, NY (US);
Assignee:
Merck & Co., Inc., Rahway, NJ (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
540249 ;
Abstract
4-Substituted-1,4-dihydropyridines are prepared by a cycloaddition reaction in which the cyclization is driven to completion, after thermal reaction, by addition of an acid. Felodipine, a vasodilator, is prepared by a cycloaddition reaction of ethyl 3-aminocrotonate with a suitably substituted dichlorobenzylidine under reaction conditions whereby the product crystallizes out of the reaction solution and may be directly isolated by filtration.