微波辐射合成4(3H)-喹唑酮

Synthesis of 4(3H)-Quinazolinone under Microwave Irradiation

以邻氨基苯甲酸和甲酰胺为原料,在无溶剂条件下采用微波辐射法合成4(3H) 喹唑酮。实验结果表明:n(甲酰胺)/n(邻氨基苯甲酸)=10,反应物加热预混合,甲酰胺分批加料,微波辐射强度为180W,微波辐射时间为6～8min时,邻氨基苯甲酸的转化率可达96%以上,4(3H) 喹唑酮的收率在94%以上,反应速率比常规加热条件下提高45倍。

Using o-aminobenzoic acid and formamide as raw materials,4(3H)-quinazolinone was synthesized without solvent under microwave irradiation and normal pressure.The results showed that the optimal reaction conditions were that,the mole ratio of formamide to o-aminobenzoic acid was 10,and microwave irradiation time was 8 min with the power of 180 W;before the reaction all o-aminobenzoic acid and a quarter of total mass of formamide were mixed at 60 ℃,then the remainder of formamide was added intermittently during the reaction.The conversation of o-aminobenzoic acid reached 96% and the total yield of 4(3H)-quinazolinone was above 94%.The reaction rate was increased by 45 times against ordinary heating.