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:
Jun. 30, 1998
Filed:
Jun. 12, 1996
Bernardus Kaptein, Sittard, NL;
DSM N.V., Heerlen, NL;
Abstract
Process for the preparation of a threo-phenylserine amide of the general formula 2 in which glycine amide is contacted with the corresponding substituted benzaldehyde of formula 3 in an excess relative to the amount of glycine amide, this taking place at a pH between 9 and 14 in the presence of a suitable solvent. The resulting phenylserine amide can subsequently be hydrolyzed to a phenylserine amide of the general formula 1, which is subsequently hydrolyzed to a phenylserine amide of the general formula 1, which is subsequently subjected to a stereoselective enzymatic hydrolysis yielding a (2S,3R) phenylserine. The non-hydrolyzed (2R,3S) phenylserine amide can be isolated as a Schiff base and be recirculated and simply racemized. The (2S,3R) phenylserine obtained can be used in the preparation of thiamphenicol or florfenicol. The threo-phenylserine amides of the general formula 1 or 2 are new intermediates in this commercially attractive process for the preparation of thiamphenicol and florfenicol.