An appropriate one-pit synthesis of dihydropyrano[2,3-c]pyrazoles and 2-amino-3-cyano-7-hydroxy-substituted-4H-chromene: derivatives using thiourea dioxide as an efficient and reusable organocatalyst

摘要

Thiourea dioxide (TUD) was used as a recyclable organocatalyst for the synthesis of 6-amino-4-aryl-5-cyano-3-methyl,1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles and 2-amino-3-cyano-7-hydroxy-4-substituted-4H-chromene derivatives via the condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one and resorcinol, respectively, With aromatic aldehydes and malononitrile in water. The organocatalyst showed similar efficiency when reused in consecutive reactions.