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. 09, 1981
Filed:
Sep. 28, 1979
Marco Croci, Milan, IT;
Gennaro Maruzzelli, Milan, IT;
Glaxo Group Limited, London, GB;
Abstract
Improvements in or relating to the manufacture of semi-synthetic penicillin antibiotics are described. More particularly an improved process for the preparation of a 6.beta.-acylamino penicillanic acid antibiotic product is described in which 6.beta.-aminopenicillanic acid (6-APA) is reacted in an inert solvent with a silylating agent to form a silylated compound of formula (I) ##STR1## wherein R.sup.1 represents a hydrogen atom or a tri(C.sub.1-6 alkyl)silyl group, and R.sup.2 represents a tri(C.sub.1-6 alkyl)silyl group and the compound of formula (I) is thereafter contacted with an acyl chloride or protected acyl chloride corresponding to the desired 6.beta.-acylamino group, the silyl groups are cleaved and the desired antibiotic product is recovered, silylation being effected using a tri(C.sub.1-6 alkyl) silylurea or tri(C.sub.1-6 alkyl) halosilane and the compound of formula (I) produced being reacted without intermediate isolation with the acyl chloride or protected acyl chloride, wherein acylation is effected in the presence of a hydrogen halide acceptor mixture comprising in excess of 0.15 and preferably up to 3.00 moles of urea per mole of 6-APA; in excess of 0.15, and preferably up to 1.30 moles of bis-tri-(C.sub.1-6 alkyl)silylurea per mole of 6-APA; and in excess of 0.25, and preferably up to 3.30 moles of tri-(C.sub.1-6 alkyl)-ammonium halide per mole of 6-APA. The process is especially useful for the preparation of ampicillin and amoxycillin in high yield and high purity.