This work has been carried out to investigate the synthetic potential of 2-cyano-N-(1,5-dimethyl- 3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide (46) as key intermediate for a variety of heterocycles incorporating (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4- yl)carboxamide moiety. Examples of the target compounds are functionalized [1,2,3]triazole 137, [1,2,4]triazolo[5,1-c] [1,2,4]triazine 142, pyrazolo[5,1-c][1,2,4]triazine 145, pyridines 149, 155, thiadiazole derivative 165, thiazole derivative 170, novel hydrazonoyl chlorides 172, 174, novel bis-hydrazonoyl chlorides 176, 177, and bis-thiadiazole derivative 180. Also the study was included the biological screening of synthesized products...