活性炭固载磷钨酸催化合成2-异丙基-1,3-苯并二氧五环

Catalytic Synthesis of 2-Isopropyl-1,3-benzodioxolane by Phosphotungstic Acid Supported on Activated Carbon

以邻苯二酚和异丁醛为原料 ,活性炭固载磷钨酸为催化剂合成了杀虫剂呋喃丹的中间体2 -异丙基 - 1,3-苯并二氧五环。采用正交实验法考察了原料配比、催化剂的固载量及其用量和带水剂用量等因素对缩合收率的影响。其最优工艺条件是 :n(邻苯二酚 )∶n(异丁醛 )∶m(催化剂 )∶v(带水剂 )为 1mol∶1.5mol∶10 g∶2 0 0ml,催化剂的固载量为 2 3.6 % ,反应在回流温度下进行 ,反应时间约 4h ,收率可达 90 .8%。催化剂可重复使用。

2-Isopropyl 1,3 benzodioxolane was synthesized from catechol and isobutyric aldehyde using the phosphotungstic acid supported on activated carbon as catalyst.The effects of ratio of reactants,supported quantity and amount of catalyst and amount of dehydrating agent were investigated by the orthogonal test.The results showed that the optimum condensation conditions are as follows:catechol∶isobulyric aldehyde∶catalyst∶dehydrating agent is 1mol∶1.5mol∶10g∶200ml;Supported quantity of catalyst is 23.6%;reaction temperature is reflux temperature;reaction time is about 4h.The yield can reach 90.8% under the optimum conditions and the catalyst can be used repeatedly.