Synthesis Of The Side Chains Of Cephalosporins

Three new way to prepare cis-2-furyl-2-(methoxyimino) acetic acidwere discussed, and a new technologic process of preparation ofcis-2-methoxyimino-2-(2'-aminothiazol-4'-yl)-4-acetic acid was sugges-ted.Cis-2-furyl-2-(methoxyimino) acetic acid was prepared from 2-furan(oxo) acetic acid after condensation with methoxylamine hydrochloridein the base solution, the yield was 58.1%.This paper report three new way to prepare cis-2-furyl-2-(methoxyimino) acetic acid:1.2-Furan (oxo) acetic acid was prepared from 2-acetyl-furan afteroxidized by sodium permanganate at 5℃, the yield was 27.2%2.2-Furan (oxo) acetic acid was prepared from 2-ketone-furan aftercyanation, hydrolysis and oxidation, the yield was 17.3%.3.2-Furan (oxo) acetic acid was prepared from 2-acetyl-furan afternitrosation, hydrolysis, and oxidation, the yield was 65.1%. The totalyield of c/s-2-furyl-2-(methoxyimino) acetic acid was 37.8%.This paper also report a new technologic process ofcis-2-methoxyimino-2-(2'-aminothiazol-4'-yl)-4-acetic acid which wereprepared from ethyl acetoacetate. The preparation of ethyl cis-2-methoxyimino-2 (2-aminothiazo-4-yl) acetate was carried out in "apot" in which the following steps occurred sequentially: bromination,nitrosation, cyclocondensation and methylation, the yield was 72.2%.Cis-2-methoxyimino-2-(2'-aminothiazol-4'-yl)-4-acetic acid wasprepared from ethyl cis-2-methoxyimino-2(2-aminothiazo-4-yl) acetateafter hydrolysis by hydrochloric acid, the yield was 92.6%, the totalyield was 66.8 %. The new synthetic process improved the yield,simplified the operation and shortened the total reaction, so it would bepotential in industrial application.