介孔分子筛MCM-41负载磷钨酸催化合成香兰素1,2-丙二醇缩醛

Synthesis of vanillin 1,2-propylene glycol acetal catalyzed by mesopore materials MCM-41 supported phosphotungstic acid hydrate

以香兰素和1,2-丙二醇为原料,以介孔分子筛MCM-41负载磷钨酸为催化剂,环己烷为带水剂,合成了香兰素1,2-丙二醇缩醛.考察了醛醇物质的量比、反应时间、带水剂用量、催化剂用量及负载量对产率的影响.实验表明,介孔分子筛MCM-41负载磷钨酸是合成香兰素1,2-丙二醇缩醛的理想催化剂,较优反应条件为:n(香兰素)∶n(1,2-丙二醇)=1∶2.4,负载量为50%,催化剂用量为反应物总质量的2.0%,带水剂环己烷15mL,回流反应2.0h,香兰素1,2-丙二醇缩醛的收率达92%以上.

Vanillin 1,2-propylene glycol acetal was synthesized using 1,2-propylene glycol and vanillin as starting materials,mesopore materials MCM-41 supported phosphotungstic acid hydrate as catalyst and cyclohexane as water stripping agent.Effects of factors on yield of product,such as molar ratio of the reactant,reaction time,the amount of water stripping agent and catalyst dosage and supported contents,were investigated.Experimental results showed that the preferential conditions are：the molar ratio of vanillin to 1,2-propylene glycol is 1∶2.4;supported contents is 50%,the dosage of catalyst is 2.0% of the total weight of the reactants;the amount of cyclohexane as water stripping agent is 15 mL;the reaction time is 2.0 h.Under these conditions,the yield can achieve 92%.