高效农药异戊烯酸乙酯的新催化合成

以经硫酸功能化的中孔分子筛MCM-41为催化剂,直接用反应物乙醇作带水剂,以乙醇和异戊烯酸为原料,采用分批补充乙醇的工艺方法合成了高效农药异戊烯酸乙酯,并考察了催化剂用量、反应物物质的量比、反应温度和反应时间对反应转化率和选择性的影响。通过催化剂对比试验得出,经硫酸功能化的中孔分子筛MCM-41是合成异戊烯酸乙酯的高效且环保的固体酸催化剂。该反应最佳的合成条件是:异戊烯酸和乙醇的物质的量配比为1∶8,催化剂用量为异戊烯酸质量的1.5%,反应时间为5h,反应在剧烈回流温度下进行。在此条件下,异戊烯酸的转化率可达89.4%,产品纯度大于99.6%。该反应条件温和,操作简单,催化剂的寿命长,产物提纯容易,适合工业化生产。

New Catalytic Synthesis of Isoprene Ene Acid Ethyl Ester as Efficient Pesticide

In this paper,isoprene ene acid ethyl ester was synthesized as an efficient pesticide from isoprene ene acid and ethanol using mesoporous molecular sieves MCM-41 functionalized by sulfuric acid as catalyst and ethanol as dehydrating agent for the first time.The process method of replenishing ethanol in batches was used.The factors such as catalyst amount,reactant ratio,reaction temperature and reaction time which could affect the conversion and selectivity were investigated.The result of catalyst contrast experiment showed that the mesoporous molecular sieves MCM-41 functionalized by sulfuric acid was the efficient and environmental solid acid catalyst for the catalytic synthesis of isoprene ene acid ethyl ester.The experimental result showed that the optimum conditions were as follows: the mole ratio of isoprene ene acid to ethanol was 1∶8;the amount of catalyst was 1.5% of isoprene ene acid(W/W);the reaction time was 5 h at reflux temperature.Under the conditions above,the conversion reached 89.4% and the purity of the product was over 99.6%.The reaction conditions were mild,with the process simple,the catalyst life long and the product easily purified,thereby suitable for industrialized production.