Succinyl Synthesis And Characterization Of The Ethyl Derivatives

Monoethyl ester succinic acid (MEESA) and its derivatives were widely used in medicine, agriculture and other fields. The investigation on the synthesis of MEESA and its derivatives in abroad and domestic is scarce. Therefore, it's important to study the optimum reaction conditions of MEESA and its derivatives. An important medicine intermediate 4-(N,N'-diphenylhydrazino) butyric acid ethyl ester was synthesized firstly using succinic anhydride and ethanol by the preparing of monoethyl succinate, diethyl succinate, ethyl succinyl chloride and 3- (N, N'- diphenylhydrazinocarbonyl) propionic acid ethyl ester. The structure of the products were characterized by IR, ¹HNMR and MS. Effect of the reaction temperature, reaction time, reactants ratio and choice of catalyst on the reaction was investigated through orthogonal experiments and single variable experiments. The optimum reaction conditions were obtained. The esterify reaction was catalysed by strong acid cation exchange resin. The catalyst can be reused by improvement of cyclization. The optimum reaction condition of ethyl succinyl chloride was obtained through improving of the reaction time, temperature and material ratio. The yield of the product was 95%. The synthesis of 3- (N, N'-diphenylhydrazinocarbonyl) propionic acid ethyl ester had easy operation, simple artificial route and little environmental pollution. NaBH₄-I₂ as a compatible reducting agent of carbonyl group was found through experiments, which was a potential new method with little by-product, little environmental pollution and easy purification.