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. 01, 1992
Filed:
Nov. 26, 1991
Johannes R Jansen, Monheim, DE;
Hans-Joachim Knops, Monheim, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
The invention relates to a process for working up to crystallization mother liquor which is obtained in the resolution of the racemate of 1-(4-chlorophenyl)-ethylamine of the formula (I) with S-(-)-N-phenylcarbamoyllactic acid of the formula (II) by removing the ethanol from the ethanolic crystallization mother liquor by distillation in a 1st step and stirring the residue which remains with tert.-butyl methyl ether or toluene in a second step and it being possible to employ the resulting crystalline salt of (R/S)-1-(4-chlorophenyl)-ethylamine and (S)-(-)-N-phenylcarbamoyllactic acid directly again for the resolution of the racemate. The (S)-form of the amine is mainly present in the mother liquor and can be racemised and added to the resolution of the racemate again.