室温下氨基磺酸催化合成喹噁啉衍生物

用廉价、无毒、易得的氨基磺酸作为催化剂,以二氯甲烷为溶剂,用芳香、杂环及脂肪1,2-二酮分别与1,2-二胺在室温下进行缩合反应得到喹噁啉衍生物。考察了溶剂、催化剂用量、反应时间对产物收率的影响,优化的工艺条件为:n(二酮)∶n(二胺)∶n(氨基磺酸)=1∶1∶0.15,反应温度25℃,反应时间6 h,产物最终收率均超过75%。该反应放大200倍后,即在1 L溶剂中,用1 mol的反应物反应时,在优化的工艺条件下产率仍然可以达到70%。氨基磺酸可以循环使用5次而产率保持稳定。

Synthesis of Quinoxaline Derivatives Catalyzed by Sulfamic Acid at Room Temperature

Several aromatic,heteroaromatic as well as aliphatic 1,2-diketones were subjected to condensation with various aromatic 1,2-diamines using the inexpensive,nontoxic and readily available sulfamic acid as catalyst in dichloromethane to afford quinoxaline derivatives.The optimal reaction conditions were n(diketone)∶n(diamine)∶n(sulfamic acid)=1∶1∶0.15,reaction time 6 h and reaction temperature 25 ℃.The product yield exceeded 75%.When the reaction was magnified 200 times with 1 mol reactants in 1 L solvent under the optimal conditions,the yield still reached 70%.Sulfamic acid can be used five times with recycle without any loss in yield.