以水作溶剂微波法合成1,4-二氢苯并咪唑并[1,2-a]嘧啶类衍生物

以芳香醛、2-氨基苯并咪唑和丙二腈为原料,用传统法和微波辐射法三组分一锅煮法合成1,4-二氢苯并咪唑并1,2-a]嘧啶类化合物。反应均在无催化剂条件下以水作反应溶剂进行。结果表明,采用微波辐射优于常规方法,三组分摩尔比n(2-氨基苯并咪唑)∶n(丙二腈)∶n(取代苯甲醛)=1∶1.1∶1,辐射功率400 W,时间为6～8 min时,1,4-二氢苯并咪唑并1,2-a]嘧啶的收率在85%以上,反应速率比常规加热条件下提高70倍。通过荧光发射光谱研究证实,该系列化合物具有明显的荧光性质,其荧光发射峰位于480～550 nm。

Synthesis of 1,4-dihydropyrimido[1,2-a]benzimida-zole derivatives via Microwave in the solutions of water

A series of pyrimido1,2-a]benzimidazoles derivatives were synthesized by the reaction of 2-aminobenzimidazole with an aldehyde in the presence of malononitrile under microwave irradiation or classical heating conditions in water without any catalyst.The results show the optimal conditions of the reaction are as follows: the molar ratio of three components(malononitrile/aldehyde/2-aminobenzimidazole) is 1.1 and the microwave irradiation time is 6~8 min with the power of 400 W.The total yield of 1,4-dihydrop...