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:
Jul. 21, 1992
Filed:
Sep. 27, 1990
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
(7-APCA) having the formula (I) ##STR1## which is an important synthesis intermediate in the preparation of cephalosporin-like antibiotics, is prepared by treating a compound of the formula (II) ##STR2## in which R.sub.1 and R.sub.2 represent alkyl, aryl and aralkyl radicals, with a strong protonic acid or with a Lewis acid. Compound (II) is prepared by adding triphenylphosphine and alkali metal iodide to a compound of the formula (VI) ##STR3## then reacting with acetaldehyde in base. Compound (VI) is prepared by treating a compound of the formula (VII) ##STR4## with a base in a polar solvent at -70.degree. C. to 0.degree. C. Compound (VII) is prepared by treating a compound of the formula (VIII) ##STR5## with a chlorinating agent in an organic solvent.