Ultrasound Assisted One-Pot Three-Component Reaction for Synthesis of Novel Functionalized 4-Thioxo-Pyrano[2,3-c]Pyrazoles, 5-Thioxo-Pyrano[2,3-d]Pyrimidines and 5-Thioxo-Pyrido[2,3-d]Pyrimidines Catalyzed by Triethylamine

A series of novel 6-amino-4-thioxo-pyrano[2,3-c]pyrazole-5-carbonitriles, 7-amino-5-thioxo-pyrano[2,3-d]pyrimidine-6-carbonitriles and 4,7-diamino-5-thioxo-pyrido[2,3-d] pyrimidine-6-carbonitriles were achieved by facile green one-pot and three-component synthesis. The method depended on one-pot three-component reaction of readily available starting materials carbon disulfide, malononitrile and heterocyclic active methylene compounds catalyzed by triethylamine in water as solvent under ultra-sonication technique. The remarkable advantages of this method are the simple procedure; high yields, short rection time and environmentally benign method are the advantages of this protocol. There is no need for any additional chromatographic separation with this procedure. Analytical and spectroscopic methods were used to comprehensively characterize the structures of all newly products.