功能化离子液体催化合成2-氨基-2-色烯衍生物

Catalyzed Synthesis of Substituted 2-Amino-2-chromenes by Functionalized Ionic Liquid

以乙醇胺乙酸盐离子液体[H3N^＋CH2CH2OH][CH3CO2^-]／水为催化体系，在离子液体摩尔分数为10％，100℃条件下能顺利地催化一系列芳香醛、丙二腈和α-萘酚或β-萘酚三组分“一锅法”合成2-氨基-2-色烯衍生物，产率达89％～98％。方法操作简单、产率高、反应时间短，离子液体可重复、对环境友好。以对氯苯甲醛、丙二腈和α-萘酚为模板反应，离子液体可重复使用3次，其催化活性没有明显降低，同时还探讨了该反应体系下的可能反应机理。

An efficient and convenient method for the synthesis of 2-amino-2-chromenes has been achieved through the ‘one-pot＇ three-component condensation reaction of aromatic aldehydes, malononitrile and α- or β-naphthol in the presence of 10% mol of functionalized ionic liquid, 2-hydroxyethlammonium acetate （[H3N^＋CH2CH2OH] [CH3CO2^- ] ）, in water at 100 ℃ to afford the corresponding compounds in 89% 98% yields. The present protocol offers several advantages, including simple work-up procedure, high yields, short reaction time and moreover the ionic liquid reusability and benignity to the environment. For the reaction of benzaldehyde, malononitrile and a-naphthol, the ionic liquid can be recycled at least 3 times without the significant loss of activity. A possible reaction mechanism is proposed under the reaction conditions.