Process for preparing 3-cyclic ether substituted cephalosporin and intermediates for such a preparation

摘要

The process of the present invention and the preparation of the compound of the present invention are illustrated in the following reaction schemes. Except where otherwise indicated, in the reaction schemes and discussion that follow, substituents R1, R2, R3, L, A1, A2 and X are as defined above unless otherwise described. This invention relates to a novel process for the preparation of 3-cyclic-ether-substituted cephalosporins of formula I wherein the group CO2R1 is a carboxylic acid or a carboxylate salt and R2 has the formula: wherein A1 is selected from the group consisting of C6-10aryl, C1-10heteroaryl and C1-10heterocyclyl; A2 is selected from the group consisting of hydrogen, C1-6alkyl, C3-10cycloalkyl, C6-10aryl, C1-6alkyl(CO)(C1-6)alkyl-O-, HO(CO)(C1-6)alkyl, mono-(C6-10aryl)(C1-6alkyl), di-(C6-10aryl)(C1-6alkyl) and tri-(C6-10aryl)(C1-6alkyl); from a zwitterionic compound of formula II; or from a compound of formula V: wherein R2 is as defined above and R3 is para-nitrobenzyl or allyl. The invention also relates to the preparation of the above compounds of formulae II and V.