乙酰丙酮钙催化剂催化合成甲基丙烯酸二甲氨基乙酯

以CaCl2和乙酰丙酮为原料,在碱性条件下合成了乙酰丙酮钙催化剂;通过元素分析、红外光谱和1H核磁共振表征确证了所制得的乙酰丙酮钙催化剂的结构。并将乙酰丙酮钙催化剂用于催化甲基丙烯酸甲酯(MMA)与二甲氨基乙醇(DMAE)进行酯交换反应合成甲基丙烯酸二甲氨基乙酯(DMA),研究了乙酰丙酮钙催化剂用量、原料配比、反应时间对酯交换反应的影响。实验结果表明,与传统的均相催化剂相比,乙酰丙酮钙催化剂对酯交换反应的催化活性和选择性高,当乙酰丙酮钙用量为DMAE质量的1.2%、n(MMA)∶n(DMAE)=2.5、反应时间6h、反应温度98~110℃时,DMAE转化率为98.5%,DMA收率为96.7%。乙酰丙酮钙催化剂重复使用4次后,DMA选择性下降了17.1%。

Synthesis of 2-(Dimethylamino) Ethyl Methacrylate by Transesterification over Calcium Acetylacetonate Catalyst

Calcium acetylacetonate catalyst was prepared from calcium chloride and acetylacetone and was characterized by means of elemental analysis, IR and 1H NMR. 2-(Dimethylamino) ethyl methacrylate(DMA) was synthesized from methylacrylate(MMA) and dimethylaminoethanol(DMAE) on calcium acetylacetonate catalyst. Influences of catalyst dosage, mole ratio of MMA to DMAE and reaction time on yield and selectivity of DMA were investigated. Catalytic activity and selectivity of calcium acetylacetonate catalyst in transesterification are higher than those of traditional catalysts. Under optimal reaction conditions: mass fraction of calcium acetylacetonate catalyst 1.2%, mole ratio of MMA to DMAE 2.5, reaction time 6 h and temperature 98-110 ℃, conversion of DMAE and yield of DMA can reach 98.5% and 96.7%, respectively. After calcium acetylacetonate catalyst was reused for 4 times, yield and selectivity of DMA remarkably reduced by 17.1%.