申请人:American Home Products Corporation
公开号:US03932398A1
公开(公告)日:1976-01-13
Penicillin sulfoxides are converted to 3-halo-3-methyl-cepham-4-carboxylic acid esters and amides or the corresponding cephem derivatives by heating the penicillin sulfoxide precursor in a polyhaloalkane solvent to a temperature between 50.degree. to about 150.degree.C. in the presence of an equimolar amount of a neutral or basic catalyst, respectively. The catalysts employed are bases such as pyridine, picoline, lutidine, quinoline, isoquinoline, dimethylaniline or a quaternary ammonium salt. The 3-halo-cepham intermediates produced with a quaternary ammonium catalyst are dehydrohalogenated to afford known cephem derivatives or converted to the free 4-carboxylic acid and the alkali metal, alkaline earth metal or ammonium salts thereof to afford novel antibacterial agents.
青霉素亚砜可以在多卤代烷溶剂中,在50℃到150℃的温度下,在中性或碱性催化剂的存在下,通过加热青霉素亚砜前体,转化为3-卤代-3-甲基头孢烯-4-羧酸酯和酰胺或相应的头孢烯衍生物。所采用的催化剂是碱性物质,如吡啶、哌啶、戊啶、喹啉、异喹啉、二甲基苯胺或季铵盐。使用季铵盐催化剂产生的3-卤代头孢烯中间体可以脱卤反应,从而得到已知的头孢烯衍生物,或转化为自由的4-羧酸和碱金属、碱土金属或铵盐,以制备新型抗菌剂。