固定化脂肪酶催化合成丙二酸单对硝基苄酯

Synthesis of mono-p-nitrobenzyl malonate catalyzed by immobilized lipase

以脂肪酶为催化剂,在甲苯介质中直接催化丙二酸和对硝基苄醇合成丙二酸单对硝基苄酯,并对酶法合成反应条件进行优化。确定最佳反应条件为：以甲苯为介质的20 mL反应体系中,Novozym435质量浓度为3 g/L,对硝基苄醇质量浓度为4 g/L,对硝基苄醇与丙二酸摩尔比为4∶5,反应温度为50℃,反应时间为8 h,丙二酸单对硝基苄酯收率达到最大值873%。Novozym 435重复使用6次后,丙二酸单对硝基苄酯收率约为70%。丙二酸单对硝基苄酯的结构组成通过核磁共振氢谱（^1H NMR）进行了表征和确认。

The synthesis of mono-p-nitrobenzyl malonate in toluene by using malonic acid and 4- nitrobenzyl alcohol as raw materials and lipase as catalyst was investigated, and the reaction conditions of enzymatic synthesis were optimized.The optimum conditions were 3 g/L of Novozym 435 and 4 g/L of 4- nitrobenzyl alcohol, 4 ： 5 of 4-nitrobenzyl alcohol and malonic acid mole ratio, 50℃ of reaction temperature,8 h of reaction time.Under above conditions, the yield of mono-p-nitrobenzyl malonate could reach 87.3 %. Results demonstrated that the yield of mono-p-nitrobenzyl malonate retained 70% after Novozym 435 being used 6 times. The structure of mono-p-nitrobenzyl malonate was characterized and determined by nuclear magnetic resonance hydrogen spectrum （^1H NMR）.