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:
Oct. 05, 1993
Filed:
Sep. 02, 1992
Applicant:
Inventor:
Daniel E Martin, Lee's Summit, MO (US);
Assignee:
Merrell Dow Pharmaceuticals Inc., Cincinnati, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
540491 ; 540490 ;
Abstract
An amino-acid ester compound can be cyclized into a cyclic amido-carbonyl compound by contacting the amino-acid ester compound in a liquid medium with a heterogeneous acidic ion-exchange substance. For example, 2-hydroxy-3-(2-aminophenylthio)-3-(4-methoxyphenyl)propionic acid, methyl ester, threo form, can be cyclized in an aqueous mixture into cis-2-(4-methoxyphenyl)-3-hydroxy-2,3-dihydro-1,5-benzothiazepin-4(5H)-one by employing a sulfonated polystyrene-divinylbenzene ion-exchange resin in its acid form, e.g., Dowex.RTM. 50X4-400. at yields exceeding 85 percent of theory, and the product can be used to make diltiazem hydrochloride.