Synthesis of L-(+)-diethyl tartrate by a strong acid cation exchange resin

L-(+)-diethyl tartrate was synthesized catalyzed by a strong acid cation exchange resin from L-(+)tartaric acid and ethanol, using a strong acid cation exchange resin and carbon tetrachloride as a catalyst and a solvent,by refluxing for about 5h.The structure of the product is confirmed by IR, the specific rotator power is determined by polarimeter.The effect of molar ratio of reactants,amount of solvent and catalyst,and reaction temperature on the yield were discussed by orthogonal test.The optimum reaction conditions were as follows:the molar ratio of L-(+)-tartaric acid and n-ethanol at 1∶5, resin at 20g, carbon tetrachloride at 70mL and reaction temperature at 69℃.Under the optimum condition,the yield of L-(+)-diethyl tartrate was over 93%.The resin has longer catalyst life, and good regeneration ability.