三聚磷酸二氢铝/载硫硅藻土催化合成苯甲醛乙二醇缩醛

Synthesis of Benzaldehyde Glycol Acetal Catalyzed by Aluminum Dihydrogen Tripolyphosphate/Loaded Sulfur Diatomite

以苯甲醛、乙二醇为原料,三聚磷酸二氢铝/载硫硅藻土为催化剂合成苯甲醛乙二醇缩醛。采用单因素实验,考察了醇醛摩尔比、催化剂用量及反应时间对产品收率的影响;利用中心组合设计实验和响应面实验获得较佳工艺条件。结果表明,在三聚磷酸二氢铝/载硫硅藻土催化合成苯甲醛乙二醇缩醛中,各因素影响的顺序为:醇醛摩尔比>反应时间>催化剂用量。多元回归模型方差分析结果显示优化反应条件为:反应温度115℃,反应时间1.23 h,醇醛摩尔比2.6,苯甲醛21 g,催化剂用量为反应物总质量的1%,带水剂甲苯30 m L,苯甲醛乙二醇缩醛的收率为88.1%。该催化剂经5次重复使用后,收率仍可达86.1%。

Benzaldehyde glycol acetal was synthesized from benzaldehyde and ethylene glycol using aluminum dihydrogen tripolyphosphate/loaded sulfur diatomite as catalyst.The effect of molar ratio of alcohol to aldehyde,catalyst amount and reaction time on the yield was studied by single-factor experiments.Box-Behnken design and response surface analysis were used to obtain the optimized technical conditions of the synthesis of benzaldehyde glycol acetal.The results show that the three main influencing factors are in the order as follows：aldehyde alcohol mole ratio〉 reaction time〉 the quantity of catalyst.The variance analysis of multiple regression model shows that the optimal technical conditions are：temperature 115 ℃,molar ratio of benzaldehyde to glycol 1 ∶ 2.6,benzaldehyde 21 g,reaction time 1.23 h,the quantity of catalyst 1%,and water-carrying agent of cyclohexane 10 m L.Under these conditions,the yield of benzaldehyde glycol acetal is above 88.1%.After the catalyst was repeatedly used five times,the yield of benzaldehyde glycol acetal still was 86.1%.