Abstract

Synthesis of some novel pyrazole derivatives as potent antimicrobial agents

Author(s): 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