A simple and convenient approach to the synthesis of coumarin-containing dihydropyrano[2,3-c]pyrazoles via four-component reaction of β-dicarbonyl compound, phenylhydrazine, aromatic aldehydes and malononitrile in EtOH catalyzed by l-proline under ultrasonic irradiation is described. The reaction gives the coumarin-containing dihydropyrano[2,3-c]pyrazoles in good to excellent yields at room temperature
一种简便的方法来含香豆素的二氢吡喃并[2,3-的合成Ç ]吡唑通过β二羰基化合物,苯肼,芳香醛和丙二腈在EtOH的四组分反应催化的通过升超声波照射下脯氨酸被描述。该反应在室温下以良好或优异的产率得到了包含香豆素的二氢吡喃并[2,3- c ]吡唑。该方法具有许多优点,例如反应时间更短,环境友好,后处理步骤简单和产率更高。