六甲基二硅胺烷催化芳香醛与2,2-二甲基-1,3-二噁烷-4,6-二酮的缩合反应

Knoevenagel Condensation Reaction of 2,2-Dimethyl-1,3-Dioxane-4,6-Dione and Aromatic Aldehydes by Hexamethyldisilazane

在六甲基二硅胺烷的催化作用下,以芳香醛与2,2-二甲基-1,3-二噁烷-4,6-二酮为原料,经缩合反应合成了10种芳基亚甲基麦氏酸化合物.考察了反应温度、反应时间、催化剂用量等因素对反应的影响.确定了最佳反应条件为：取0.1 mol 2,2-二甲基-1,3-二噁烷-4,6-二酮,n（2,2-二甲基-1,3-二噁烷-4,6-二酮）∶n（芳香醛）=1.0∶1.1,催化剂用量为0.1 mol,反应温度为室温,反应时间为1.0 h,在上述反应条件下,产品收率可达86.8%~92.1%.

Ten kinds of arylidene Meldrum’s acids was synthesized from 2,2-dimethyl-1,3-dioxane-4,6-dione and aromatic aldehydes using hexamethyldisilazane as catalyst.The effects of reaction temperature,reaction time,catalyst dosage on the yield were investigated.The optimum conditions were as follows： 0.1 mol malonic acid,n（malonic acid）∶n（aromatic aldehyde）=1.0 ∶1.1,the amount of catalyst 0.1mol,reaction temperature was at room temperature,reaction time 1.0 h.Under above reactionconditions,the product yields achieved up to 86.8%～ 92.1%.