La(OTf)_3催化合成2,2-二甲基-1,3-二噁烷-4,6-二酮

Catalytic Synthesis of 2,2-Dimethyl-1,3-dioxane-4,6-dione with La(OTf)_3

研究了在三氟甲基磺酸镧(La(OTf)3)的催化条件下,以丙二酸和丙酮为原料,乙酸酐为缩合剂合成了2,2-二甲基-1,3-二噁烷-4,6-二酮。考察了酸酮摩尔比、反应温度、反应时间及催化剂用量等因素对反应的影响。确定了其最佳反应条件为:取0.1 mol丙二酸,n(丙二酸)∶n(丙酮)=1.0∶1.1(mol/mol),催化剂用量为0.2 g/0.1 mol丙二酸,反应温度30℃,反应时间为3.0 h,在上述反应条件下,产品收率可达77.1%。

2,2-Dimethyl-1,3-dioxane-4,6-dione was synthesized from malonic acid and acetone using La（OTf）_3,as catalyst and acetic anhydride as condensing reagent.The effects of the molar ratio of malonic acid to acetone,reaction temperature,reaction time and catalyst dosage on yield were investigated.The optimum conditions were as follows： 0.1 mol malonic acid,n（malonic acid）∶n（acetone）=1.0∶1.1（mol/mol）,amount of catalyst 0.2 g/0.1 mol malonic acid,reaction temperature of 30 ℃,reaction time of 3.0 h.Under the above reaction conditions,the product yield reached 77.1%.