Catalytic systems containing p-toluenesulfonic acid monohydrate catalyzed the synthesis of triazoloquinazolinone and benzimidazoquinazolinone derivatives

A variety of quinazolinones are readily prepared via one-pot three-component reaction in good to excellent yields. The desired products were obtained from the reaction of dimedone, various aldehydes with 2-aminobenzimidazole or 3-amino-1,2,4-triazole under mild reaction conditions using p-toluenesulfonic acid monohydrate as effective catalyst in acetonitrile as solvent. Starting from the corresponding available materials, this friendly and environmentally free-metal procedure has been successfully extended to the synthesis of triazoloquinazolinones and benzimidazoquinazolinones. The salient advantages of this method are mild reaction conditions, nontoxic and inexpensive catalyst, environmentally benign, high to excellent yields, shorter reaction times, easy operation, and no column chromatographic separation.