以顺酐为原料 ,磷钨酸为酯化催化剂 ,一种含溴的氧化剂为异构化催化剂 ,通过精馏分水 ,一锅法合成富马酸二甲酯。考察了酯化时间、酯化催化剂用量、酐醇摩尔比、异构化催化剂用量、异构化温度、异构化时间等因素对反应产率的影响 ,并得到了最佳工艺条件 ,即顺n(酐 )∶n(甲醇 ) =1∶8,磷钨酸的用量为顺酐用量的 6% ,酯化回流 4h ,蒸出过量甲醇 ,然后加入顺酐用量 1 .6%的异构化催化剂 ,在 95～ 1 0 5℃温度下反应 3 0min ,产率超过 77%。精馏分水法较好地解决了甲酯化反应去水的问题 ;所采用的酯化催化剂和异构化催化剂对设备腐蚀较小 ,产品后处理简单 ,无三废。并且探讨了异构化机理 Using maleic anhydride as raw material, phosphotungstic acid as the esterification catalyst, a bromine-containing oxidant as the isomerization catalyst, and one-pot synthesis of dimethyl fumarate through rectification and separation. The effects of esterification time, the amount of esterification catalyst, molar ratio of anhydrous alcohol to alcohol, the amount of isomerization catalyst, isomerization temperature and isomerization time on the reaction yield were investigated. The optimum conditions n (anhydride): n (methanol) = 1: 8, the amount of phosphotungstic acid was 6% of maleic anhydride, esterification reflux 4h, distilled off excess methanol, and then added maleic anhydride content of 1.6% The catalyst was reacted at 95 ~ 105 ℃ for 30min with a yield of over 77%. The rectification water separation method solves the problem of dewatering the methyl esterification reaction well. The esterification catalyst and isomerization catalyst are less corrosive to the equipment, and the product has simple post-treatment and no wastes. The mechanism of isomerization is also discussed