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以固体酸碱为催化剂,研究了碳酸二甲酯与环戊酮合成己二酸二甲酯的反应,并考察了反应温度、反应时间、催化剂用量和原料摩尔配比等因素对反应结果的影响.结果表明,固体酸催化剂不利于己二酸二甲酯的生成,而具有中强碱位的MgO对反应具有较好的催化性能.当以MgO为催化剂,在反应温度为260℃,反应时间5h,催化剂用量为反应物质量的1.5%,原料摩尔配比为环戊酮/DMC=1/4的最佳条件下,环戊酮的转化率和己二酸二甲酯的选择性分别达到85.5%和50.9%.同时,反应的主要副产物为环戊酮自身缩合的产物(2-环戊烯基环戊酮)以及环戊酮的甲基化产物(2-甲基环戊酮、2-甲基己二酸二甲酯)等.另外,反应是通过固体碱活化环戊酮的α-H进行,而2-甲氧基羰基环戊酮是生成己二酸二甲酯的中间体.
The solid acid-base catalyst was used to study the reaction of dimethyl carbonate with cyclopentanone to synthesize dimethyl adipate. The effects of reaction temperature, reaction time, amount of catalyst and molar ratio of raw materials on the reaction results were investigated .The results showed that the solid acid catalyst was not conducive to the formation of dimethyl adipate, while the MgO with moderate alkali sites had good catalytic performance for the reaction.When MgO was used as the catalyst, the reaction temperature was 260 ℃, the reaction time 5h, the amount of catalyst was 1.5% of the mass of reactants, the conversion of cyclopentanone and the selectivity of dimethyl adipate reached 85.5 under the optimal conditions of molar ratio of cyclopentanone / DMC = 1/4 % And 50.9% .At the same time, the main byproducts of the reaction were the product of cyclopentanone self-condensation (2-cyclopentenylcyclopentanone) and the methylated product of cyclopentanone (2-methylcyclopentanone, 2 - dimethyl adipate), etc. In addition, the reaction is carried out by activating α-H of cyclopentanone by a solid base, and 2-methoxycarbonylcyclopentanone is an intermediate for producing dimethyl adipate .