This research involved the conversion of sulfadiazine into compound 2-chloro-N-(4-(N-(pyrimidin-2-yl) sulfamoyl) phenyl) acetamide [A] through the reaction of sulfadiazine with chloroacetyl chloride in the presence of diethylamine in dimethylformamide as solvent. Then prepared the hydrazine derivative of sulfadiazine 2-hydrazinyl-N-(4-(N-(pyrimidin-2-yl) sulfamoyl) phenyl) acetamide [B] through the interaction of compound [A] with hydrazine in dimethylformamide as solvent. Followed by chalcones preparation [C1, C2, C3, C4, and C5] from the reaction of 4-aminoacetophenone with some aromatic aldehydes in a basic medium in absolute ethanol using an ice bath. Pyrazoline derivatives [BC1, BC2, BC3, BC4, and BC5] were prepared from the reaction of the hydrazine derivative of sulfadiazine [B] with chalcones in a basic medium in the presence of absolute ethanol. The pyrazole derivatives [IBC1, IBC2, IBC3, IBC4, and IBC5] were prepared from the reaction of the hydrazine derivative of sulfadiazine [B] with chalcones in the presence of glacial acetic acid and then the product was oxidized using Iodine. Synthesized compounds have been studied by their melting points, and characterized by C.H.N.S analysis, FT-IR and 1H-MNR spectroscopy and studied of biological activity.