OKISOKIOJUSURUAZECHIJINONKAGOBUTSUMOSHIKUHASONOENRUIMATAHASONOSUIKABUTSUNOSEIZOHO

摘要

NEW MATERIAL:Compounds of formula I [A' is formula II (R<3> is H, alkyl; R<4> is H, halogen, alkyl; R<5> is carboxyl; X is sulfur or oxygen atom)] or their salts or hydrates. EXAMPLE:7-Oxocephalosporanic benzhydryl ester. USE:Synthetic intermediate of azetidinones with antibiotic activity. PREPARATION:The reaction of an azetidinone bearing a disubstituted amino group of formula III (A is A') with a base such as triethylamine is followed by hydrolysis. Or, trihalomethanesulfonylating agent is made to act on the azetidinone bearing an amino group of formula IV and an acylating agent is made to react with the product or the acylation is followed by the trihalomethanesulfonylation to give the compound of formula III and the product is made to react with a base, followed by hydrolysis.