NOVEL ESTER OF 1,1-DIOXOPENICILLANIC ACID, PROCESS FOR PRODUCTION THEREOF, AND USE THEREOF AS BETA-LACTAMASE INHIBITOR

摘要

A 1,1-dioxopenicillanic acid ester represented by formula (I) (I) wherein R represents a methyl or phenyl group. The ester of formula (I) may be prepared by reacting 1,1-dioxopenicillanic acid or its salt with a compound represented by formula (III) (III) wherein R is as defined above, and X represents a halogen atom, or by oxidizing a compound of formula (V) (V) wherein R is as defined above. The ester of the formula (I) is useful as a beta -lactamase inhibitor and may be used in association with a beta -lactam antibiotic.