水介质中离子液体催化合成四氢喹唑啉

Catalytic synthesis of tetrahydroquinazoline by ionic liquids in aqueous media

摘要:

以1-丁基-3-甲基咪唑四氟硼酸盐作为催化剂，以芳香胺和2-氨基苯甲醛为原料，在水介质中通过环化缩合反应，合成了一系列四氢喹唑啉类衍生物。通过对模板反应条件的探究，确定了最优条件为：0.2 mmol 2-（1-吡咯烷基）苯甲醛（Ⅰa），0.4 mmol芳香胺（Ⅱa），30%（以Ⅰa物质的量为基准）的催化剂，1 mL H2O，90 ℃下反应6 h，可得到产率为81%的产物。同时探索了的反应底物普适性，以较好的底物范围合成了19种四氢喹唑啉类衍生物。

Abstract:

A series of tetrahydroquinazoline derivatives were synthesized by cyclization condensation in aqueous medium with 1-butyl-3-methylimidazole tetrafluoroborate as catalyst, aromatic amine and 2-aminobenzaldehyde as raw materials. By exploring the reaction conditions, the optimal conditions are determined as follows: With 0.2 mmol 2-(1-pyrrolide) benzaldehyde (Ⅰa), 0.4 mmol aromatic amine (Ⅱa), 30% (based on the amount of Ⅰa, the same below) catalyst, 1 mL H2O, at 90 ℃ for 6 h, the highest yield of 81% of the product was obtained. At the same time, the universality of the substrate was investigated, and 19 tetrahydroquinazoline derivatives were synthesized from a wide range of substrates.