Phase-Transfer Esterification of the Alkali Metal Salts of Cephalosporins and Penicillins
作者:Iñaki Ganboa、Claudio Palomo
DOI:10.1055/s-1986-31474
日期:——
Cephalosporins and penicillins can be converted into their alkyl esters in high yields by reaction of their solid sodium or potassium salts with alkyl bromides in acetonitrile in the presence of crown ethers as phase-transfer catalysts.
Compounds of the formula ##STR1## in which R is hydrogen or an acyl group, R.sub.1 is hydrogen or lower alkyl, and R.sub.2 is hydrogen, an alkali metal cation, or a readily removable ester forming group, are active antibiotics or intermediates thereto.
[EN] AN IMPROVED PROCESS FOR THE PREPARATION OF CEFOXITIN<br/>[FR] PROCEDE AMELIORE DE PREPARATION DE CEFOXITINE
申请人:ORCHID CHEMICALS & PHARM LTD
公开号:WO2004083217A1
公开(公告)日:2004-09-30
The present invention relates to an improved process for the preparation of cefoxitin of formula (I).
本发明涉及一种改进的制备化学式(I)的头孢噻肟的方法。
Direct observation by proton NMR of cephalosporoate intermediates in aqueous solution during the hydrazinolysis and .beta.-lactamase-catalyzed hydrolysis of cephalosporins with 3' leaving groups: kinetics and equilibria of the 3' elimination reaction