合成2-(3-噻吩基)丙二酸的新工艺

New Synthesis Process for 2-(3-Thienyl) Malonic Acid

设计了合成2-(3-噻吩基)丙二酸的新路线,采用配位催化碘化法,以3-溴噻吩为原料,经碘代、缩合和水解、酸化等反应合成2-(3-噻吩基)丙二酸。在正丁醇中,3-溴噻吩在CuI/N,N′-二甲基乙二胺催化下与KI进行碘代反应,得到3-碘噻吩,收率为91.73%;3-碘噻吩再在CuBr催化下与丙二酸二乙酯钠盐进行缩合反应,制得2-(3-噻吩基)丙二酸二乙酯,收率为76.30%;2-(3-噻吩基)丙二酸二乙酯经水解和酸化反应后得到最终产品2-(3-噻吩基)丙二酸,收率为82.63%。该路线合成2-(3-噻吩基)丙二酸的总收率(以3-溴噻吩计)为57.83%。

2-（3-Thienyl ） malonic acid was synthesized from 3-bromothiophene with coordinative catalyst, through a new route, namely iodination, condensation, hydrolysis and acidification. 3-Bromothiophene reacted with KI in n-butanol with CuI/N,N＇-dimethylethane-1,2-diamine as catalyst system. Yield of obtained 3-iodothiophene reaches 91.73%. The 3-iodothiophene converted to diethyl 2-（3-thienyl ）malonate by condensation with sodium salt of diethyl malonate in presence of CuBr as catalyst. Yield of obtained diethyl 2-（ 3-thienyl ） malonate is 76. 30% based on 3-iodothiophene. 2-（3-Thienyl） malonic acid was prepared by hydrolysis and acidification with a yield of 82.63 %. Total yield of 2-（3-thienyl）malonic acid by this route is 57.83% based on 3-bromothiophene.