【摘要】 采用草酸为催化剂,由醛、1,3-二羰基化合物和脲(硫脲)在无溶剂超声波辐射下,简单有效地合成了标题化合物。和传统方法相比,该方法具有反应时间短(<1.5h)、收率高(78%～92%)、分离简单等优点。更多还原

【Abstract】 A simple and efficient method for synthesis of 3,4-dihydropyrimidin-2(1H)-ones or thiones from aldehyde,1,3-dicarbonyl compound,and urea (thiourea) was described,using oxalic acid as the catalyst under ultrasonic irradiation and solvent-free conditions.The product yields could reach 78%～92%.Compared with the classical method,this method has featured short reaction time (<1.5 h),high yields (78%～92% based on aldehydes) and easiness for separation.更多还原