Synthesis and antimicrobial activity of some 1-(2,4-dinitrophenyl)-3-(3-nitrophenyl)-5-(4-substituted phenyl)-4-bromo-2-pyrazolines and 1-(2,4-dinitrophenyl)-3-(3-nitrophenyl)-5-(4-substituted phenyl)-2-pyrazolin-4-ones.

A series of 1-(2,4-dinitrophenyl)-3-(3-nitrophenyl)-5-(4-substituted phenyl)-2-pyrazolin-4-ones (4a-e) have been synthesized by the oxidation of 1-(2,4-dinitrophenyl)-3-(3-nitrophenyl)-5-(4-substituted phenyl)-4-bromo-2-pyrazolines (3a-e) with dimethylsulfoxide. The structure has been established on the basis of spectral data (IR,1H NMR). The synthesized compounds have been screened in vitro for their possible antimicrobial activity.