5-磺基水杨酸高效催化甲基叔丁基醚与甲醛合成异戊二烯

Highly efficient catalytic synthesis of isoprene from methyl tert-butyl ether and formaldehyde using 5-sulfosalicylic acid

以双功能5-磺基水杨酸为催化剂,催化甲基叔丁基醚(MTBE)与甲醛通过液相一步法高效合成异戊二烯。考察了反应条件对反应的影响。实验结果表明,适宜的反应条件为:5-磺基水杨酸用量0.1 g,反应温度150℃,反应时间180min,水用量4.65 g,环己烷用量4.65 g,MTBE与甲醛的摩尔比为12。在该条件下,甲醛的转化率可达98.5%,异戊二烯选择性为71.1%。FTIR表征以及强弱酸混合实验结果显示,5-磺基水杨酸分子内的磺酸基与羧基协同催化作用是它具有优异催化性能的原因。

Isoprene was prepared by liquid single-stage synthesis of methyl tert-butyl ether(MTBE)and formaldehyde using bifunctional 5-sulfosalicylic acid as the catalyst.The effect of the reaction conditions on reaction was investigated.The result shows that the optimal reaction conditions are 5-sulfosalicylic acid 0.1 g,reaction temperature 150℃,reaction time 180 min,water 4.65 g,cyclohexane 4.65 g,and the molar ratio of MTBE to formaldehyde 12.Under these conditions,the conversion rate of formaldehyde and the selectivity of isoprene could reach the value of 98.5%and 71.1%,respectively.According to the results of FTIR characterization and the strong and weak acid mixed experiments,the excellent catalytic performance of 5-sulfonic acid may be attributed to the synergistic effect between the sulfonic acid and the carboxylic acid groups.