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:
Nov. 11, 1980
Filed:
Aug. 28, 1978
Horst Schmand, Bad Nenndorf, DE;
Wolfgang Dannenberg, Wunstorf, DE;
Riedel-de Haen Aktiengesellschaft, Seelze, DE;
Abstract
Optically active 2-amino-2-phenylacetic acid of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3, which are identical or different, denote hydrogen, halogen, hydroxy, alkyl, acyl, or alkoxy, is prepared by asymmetrical transformation of a corresponding DL-aminophenylacetonitrile with L(+)-tartaric acid. To this end the corresponding DL-2-amino-2-phenyl-acetonitrile is reacted with approximately equimolar amounts of L(+)-tartaric acid in the presence of at least one alkanol having from 1 to 5 carbon atoms and/or at least one carbonyl compound at a temperature of from 0.degree. to 50.degree. C. and the mixture is stirred for 2 to 120 hours at the indicated temperature. The crystallized transformation product is separated, hydrolyzed by treatment with an acid and the desired product is isolated.