a convenient synthesis of different types of polyfunctional dihydropyrrol-2-ones via one-pot four component reactions of formaldehyde, dialkyl acetylenedicarboxylates and amines, catalyzed by trichloroacetic acid (cl3cco2h) at room temperature has been investigated. the significant advantages of this synthetic method are mild reaction conditions, available and inexpensive material, short reacti...

The synthesis of 3-methyl-1,4-diphenyl-7-thioxo-4,6,8,9-tetrahydropyrazolo[5,4-b] pyrimidino[5,4-e]pyridine-5-one (6) was achieved by two different one-pot multi-component synthesis (one-pot three-component and one-pot four component synthesis). Mono and dialkylation of 6 under different conditions gave compounds 7-11. The hydrazine 12 produced from reaction of 9 with N₂H₄ was subjected to reac...