一种四氢苯并吡喃及其衍生物的水相合成

制备了一种以三乙烯二胺(DABCO)为基础的离子液体;在水溶剂中,以该离子液体为催化剂催化三组分一锅法制备四氢苯并吡喃的反应,得到2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并b]吡喃;考察了反应时间、催化剂用量、催化剂加入时间、反应温度对反应收率的影响,确定了最优反应条件;由不同的芳香醛和活性亚甲基化合物制备了一系列四氢苯并吡喃衍生物,并讨论了可能的反应机理.结果表明,所选用的合成反应条件温和、时间短、收率高、后处理简单,且催化剂重复使用4次催化效果变化不大;就反应机理而言,所用催化剂具有双重催化活性.

Synthesis of a tetrahydrobenzo-pyran and its derivatives in aqueous medium

1 ,4-diazabicyclo2 .2 .2]octane （denoted as DABCO） based ionic liquid was synthe-sized .As-obtained DABCO-based ionic liquid was adopted as a catalyst to catalyze the one-pot three-component condensation reaction for synthesizing 4H-benzob]pyran derivatives in aque-ous media affording target compound 2-amino-3-cyano-4-aryl-7 ,7-dimethyl-5-oxo-4H-5 ,6 ,7 ,8-tetrahydrobenzob]pyran .The effects of reaction time ,catalyst dosage ,catalyst-adding time , and reaction temperature on the yield were investigated ,and the optimal reaction condition was established .Moreover ,various aromatic aldehydes and active methylene compounds were a-dopted as starting materials to synthesize a series of tetrahydrobenzo-pyran compounds ,and possible reaction mechanisms were discussed .Results indicate that as-established synthesis route has the advantages of mild reaction condition ,short reaction time ,high yield and easy post-treatment ,while the catalyst retains nearly unchanged activity after 4 times of recycle .In terms of the reaction mechanisms ,as-prepared DABCO-based ionic liquid catalyst exhibits dual catalytic activity .