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:
Aug. 16, 1994
Filed:
Feb. 12, 1993
Apurba Bhattacharya, Corpus Christi, TX (US);
Hoechst Celanese Corporation, Sommerville, NJ (US);
Abstract
The present invention provides a process for the production of calcium salts of hydantoic acids and which comprises the steps of reacting a hydantoin with a calcium base material such as calcium hydroxide in an aqueous medium at a sufficient temperature and for a sufficient period of time to form the calcium salt of the corresponding hydantoic acid and then separating the calcium salt of such acid from the reaction mass. This separation can include the further steps of cooling the reaction mass down to facilitate the precipitation of the acid/salt crystals and then separating the precipitate by means of filtering or centrifugating. These acids can then be subjected to a HNO.sub.2 -mediated decarbamoylation process followed by an optical resolution step to thus provide high yields of D-p-hydroxyphenylglycine which is a key synthetic immediate or building block for semi-synthetic penicillin and cephalosporins.