నైరూప్య

Synthesis of some novel pyrazole derivatives as potent antimicrobial agents

Samira T.Rabie, Mervat M.Abdelhalim, Nadia R.Mohamed

One pot reaction of pyrazolone (3) with malononitrile, different aromatic aldehydes in presence of ammonium acetate or piperidine afforded compounds (6a-c) and (7). Compound (3) reacted with different active methylenes and p-chlorobenzaldehyde to give the corresponding pyrazole derivatives (8a-c), while using p-chlorobenzaldehyde, and acetylacetone gave compound (9). Treatment of compounds 6b and/or 7 with ethanolic potassium hydroxide and excess carbon disulphide produced products (10a-b). On treating compounds (6b) and (7) with formic and/or acetic acids, the pyrido and pyranopyrimidines (11a-b) and (12a-b),were obtained. Compound (3) reacted with malononitrile and sulfur in presence of triethylamine produced compound (13) that treated with formic and acetic acids to get the thienopyrazoles (14a-b). All derivatives exhibited high antimicrobial activities