Mild Bronsted basic ionic liquids catalyzed three component synthesis of pyrazolo[1,2-a][1,2,4]triazole-1,3-dione and 2-amino-3-cyano-5,10-dioxo-4-phenyl-5,10-dihydro-4H-benzo[g]chromene derivatives

Pyrazolo[1,2-a][1,2,4]triazole-1,3-dione derivatives were synthesized via a three component reaction of arylaldehydes, 4-phenylurazole and malononitrile in the presence of a catalytic amount of 2-hydroxyethylammonium formate and 2-hydroxyethylammonium acetate as effective mild basic ionic liquids, without using any additional co-catalyst, under solvent-free conditions at room temperature in good yields. Ionic liquids as catalysts were recovered and reused. In addition, the preparation of 2-amino-3-cyano-5,10-dioxo-4-phenyl-5,10-dihydro-4H-benzo[g]chromene derivatives from the reaction of arylaldehydes, malononitrile and 2-hydroxy-1,4-dihydronaphthalene-1,4-dione under solvent-free conditions at ambient temperature in the presence of mentioned catalysts is reported. (C) 2013 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.