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. 12, 1977
Filed:
May. 06, 1975
Gist-Brocades N.V., Delft, NL;
Abstract
Novel 6-substituted amino-penicillanic acid anhydrides useful in the process for the preparation of 7-substituted amino-desacetoxycephalosporanic derivatives comprising converting a 6-substituted amino-penicillanic acid sulfoxide into an anhydride of a 6-substituted amino-penicillanic acid sulfoxide, heating the said acid anhydride intermediate at a temperature up to at most 160.degree. C in a dry inert organic solvent with an anhydrous acid which is capable of causing ring expansion of the penam ring to a .DELTA..sup.3 -cephem ring, in the presence of a silicon-containing compound capable of (a) removing water formed during the ring enlargement of the penam structure fast enough to prevent water hydrolysis of the acid anhydride moiety present and (b) forming neutral or basic products on hydrolysis, the aforesaid acid being strong enough not to be, or not to a substantial extent to be, silylated under the reaction conditions employed, and hydrolyzing the resulting compound in situ to form the .DELTA..sup.3 -7-substituted amino-desacetoxycephalosporanic acid as such or as a salt, such as alkali metal, alkaline earth metal or amine salt.