无溶剂条件下多磺酸根酸性离子液体催化合成苯并氧杂蒽衍生物

Synthesis of Benzoxanthene Derivatives Catalyzed by Multi-SO_3H acidic Ionic Liquids under Solvent-free Conditions

采用两步法合成4种多磺酸根酸性离子液体,并以苯甲醛与β-萘酚的缩合反应为探针反应对其催化性能进行比较。以N,N′,N′′,N′′′-四丙磺酸基六亚甲基四胺四硫酸氢盐离子液体作为催化剂,探究在无溶剂条件下催化含有不同单官能团的4-取代芳香醛与β-萘酚反应制备苯并氧杂蒽类化合物,结果表明最优化反应条件:反应温度为110℃,芳香醛与β-萘酚的摩尔比为1∶2和催化剂用量为55%(基于芳香醛的质量)。除水后的离子液体催化剂可以循环使用5次,其催化活性未有明显降低。不论带有供电子基团还是吸电子基团的4-取代芳香醛均有利于缩合反应的进行。

Four kinds of multi-SO3H-acidic ionic liquids were synthesized with a two-step method and their catalytic properties were analyzed and compared with the condensation reaction of benzaldehyde andβ-naphthol as the probe reaction.The preparation of benzoxanthene derivatives through the reaction of 4-substituted aromatic aldehydes,which had different types of functional groups andβ-naphthol used N,N′,N′′,N′′′-tetrapropane sulfonic hexamethylenetetramine tetrahydrosulfate as a catalyst under solvent-free conditions was investigated.The results show that:the optimum reaction temperature,molar ratio of aromatic aldehyde toβ-naphthol,catalyst amount are 110℃,1∶2 and 55%(based on the mass of aromatic aldehydes);N,N′,N′′,N′′′-tetrapropane sulfonic hexamethylenetetramine tetrahydrosulfate after removed water can be recycled and when reused for five times,its catalytic activity has no noticeably decreasing;4-substituted aromatic aldehydes,whether the substituent is an electron-donating group or electron-withdrawing group,are beneficial to the condensation reaction.