Cephalosporin derivative production by a 7 alpha-methoxylation process and intermediates
申请人:MEIJI SEIKA KAISHA LTD.
公开号:EP0024879A1
公开(公告)日:1981-03-11
A new, efficient process is provided for the production of 7β-[(2D-2-amino-2-carboxy)-ethylthioacetamido]- 7a-methoxy-3-[(1-methyl-1H-tetrazole-5-yl)thiomethyl]-3-cephem-3-carboxylic acid which is useful as an antibacterial agent. This process is economic in using asthe starting material the inexpensive, corresponding cephem compound containing no 7a-methyoxy group on the cephem nucleus and comprises 7a-methoxylation of a protected derivative of the starting cephem compound with t-butyl hypochlorite and lithium methoxide, followed by inactivation of the excess methoxylation reagents with a trialkyl phosphite and acetic acid to prevent undesired side-reactions such as oxidation of the alkyl-thioacetyl group of the product, and further by conventional removal of the protecting groups.
本发明提供了一种生产 7β-[(2D-2-氨基-2-羧基)-乙硫基乙酰氨基]-7a-甲氧基-3-[(1-甲基-1H-四唑-5-基)硫甲基]-3-头孢环-3-羧酸的高效新工艺,该工艺可用作抗菌剂。这种工艺的经济之处在于,它以价格低廉、头庚核上不含 7a -甲氧基的相应头庚化合物为起始原料,包括用次氯酸叔丁酯和甲醇锂对起始头庚化合物的保护衍生物进行 7a -甲氧基化反应,然后使其失活、然后用三烷基亚磷酸酯和乙酸使过量的甲氧基化试剂失活,以防止不希望发生的副反应,如产物中烷基硫代乙酰基的氧化,再用常规方法去除保护基团。