2-取代-4(3H)-喹唑啉酮在Br(o)nsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型Br(o)nsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6 min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.

Microwave-Assisted Synthesis of 2-Substituted-4(3H)-quinazolinones in Br(o)nsted Acidic Ionic Liquids

Two novel Br(o)nsted acidic ionic liquids 1-(4-sulfonic)-benzyl-3-methylimidazolium hydrogen sulfate (3a) and N-(4-sulfonic)-benzyl-pyridium hydrogen sulfate (3b) were synthesized using N-methyli-midazole and pyridine as starting materials, which acted as catalyst and reaction medium for the synthesis of 2-substituted-4(3H)-quinazolinones under three-component, one-pot, and microwave irradiation conditions. Under the optimized conditions of n(2-amino-benzoic acid) : n(acylehloride) : n(ammonium acetate) : n(3a or 3b)=1: 1.2 :1.5 :0.1, the reactions completed within 6 min with the yields of 81%～95%. 3a or 3b could be recycled three times without any significant loss in catalytic activity after reduced pressure distilla-tion and drying under vacuum.