【摘要】 以柠檬醛和丙酮为原料,在微波辐射条件下,经缩合反应合成了假性紫罗兰酮,再经环化反应合成了α-紫罗兰酮。重点探讨了催化剂的种类和用量、反应物配比、微波辐射时间和功率等因素分别对缩合和环化反应的影响,确定了在微波辐射下合成α-紫罗兰酮的工艺条件:缩合反应以KF/Al2O3为催化剂(与柠檬醛的质量比为1∶1),n(柠檬醛)∶n(丙酮)=1∶10,90 W微波辐射12 min;环化反应以固体硫酸氢钠作催化剂,其用量为0.287 g,60 W微波辐射5 min。与无微波辐射条件的合成方法相比,此法大大缩短了反应时间,简化了制备工艺流程,而且假性紫罗兰酮产率由92.6%提高到98.3%,α-紫罗兰酮的产率由60.0%提高到70.1%。更多还原

【Abstract】 Pseudo-ionone was synthesized with citral and acetone as raw materials by condensation reaction under microwave radiation.The pseudo-ionone was further cyclized to form α-ionone.The influence of variety and dosage of catalyst,raw material ratio,time and power of microwave radiation on reaction were studied.Under the optimum conditions,in condensation,the best catalyst is KF/Al2O3,the mass ratio of KF/Al2O3 to citral is 1∶1,the molar ratio of citral to acetone is 1∶10,time and power of microwave radiation is 12 min and 90 W,respectively;in cyclization,the best catalyst is NaHSO4(the amount of it is 0.287 g),time and power of microwave radiation is 5 min and 60 W,respectively.The result showed that due to the action of microwave radiation the reaction time is greatly shortened and the yield is increased.The yield of pseudo-ionone increases from 92.6% to 98.3% at the optimum conditions.The yield of ionone increases 10% as campared with that without microwave radiation at the same conditions.更多还原