Addition of diazomethane to α,β-unsaturated ketones in the presence of base at low temperature gave 3-aroyl-4-aryl-2-pyrazolines (IIa).Benoylation, benzenesulfonylation and nitrosation of IIa yielded the corresponding 1-substituted derivatives (V, VI and VII) IR and (1)H-NMR spectral data established the stuctures of the new compounds.