Synthesis and antimicrobial activity of some new heterocycles incorporating antipyrine moiety.

2-cyano-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide (1) was utilized as key intermediate for the synthesis of some new coumarin 2, pyridine 3, pyrrole 4, thiazole 7, pyrido[2',3':3,4][pyrazolo[5,1-c]triazine and aminopyrazole 9. Treatment of aminopyrazole 9 with nitrous acid, 1,3-dicarbonyl compounds, enaminone, and DMF-DMA led to the formation of pyrazolo[3,4-d]triazine 10, pyrazolo[1,5-a]pyrimidines 11, 12, 14, and pyrazolo[3,4-d]pyrimidine 13, respectively. Condensation of 9 with isatin afforded Schiff base 16.