Pfizer Corporation

David L Hageman

Thomas C Crawford

Hiroshi Kondo

John Adams Lowe, Iii

Fumitaka Ito

Fredric J Vinick

Susumu Nakanishi

Dihydropyridine derivatives as bradykinin antagonist

A process for preparing halomethyl esters of penicillanic acid sulfone, intermediates to beta-lactamase inhibitors, from the corresponding substituted thiomethyl and sulfinylmethyl esters and a halogenating agent. The thiomethyl and sulfinylmethyl esters of penicillanic acid sulfone are useful intermediates.

Process for preparing esters of penicillanic acid sulfone

6'-Aminopenicillanoyloxymethyl penicillanate 1,1-dioxide is prepared by a two-step procedure. The first step consists of coupling a salt of a 6-(protected amino)penicillanic acid with a halomethyl, an alkylsulfonyloxymethyl or an arylsulfonyloxymethyl ester of penicillanic acid 1,1-dioxide, to give a 6'-(protected amino)penicillanoyloxymethyl penicillanate 1,1-dioxide, wherein the protection at the 6-position has been achieved by coupling the 6-aminopenicillanic acid with a beta-dicarbonyl compound. The second step consists of removal of the protecting group on the 6'-amino group, using aqueous acid. 6'-Aminopenicillanoyloxymethyl penicillanate 1,1-dioxide is a chemical intermediate for preparing antibacterial agents. Also claimed are the 6'-(protected amino)penicillanoyloxymethyl penicillanate 1,1-dioxide compounds used as intermediates in the process of this invention.

Process for 6'-amino-penicillanoyloxymethyl penicillanate 1,1-dioxide

Esters of penicillanic acid sulfone

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Colchester, CT, United States of America

David L Hageman