Synthesis and antimicrobial activity of chalcones and pyrazolines

Chalcones are 1,3-diphenyl-2-propene-1-one, in which two aromatic rings are linked by a three carbon ?,?-unsaturated carbonyl system. They have displayed a broad spectrum of biological activities. In this view it was proposed to synthesize some novel pyrazolines from chalcones. Chalcones are prepared by treating 2-acetyl-5-bromothiophene with different aromatic compounds. These chalcones on condensation with phenyl hydrazine HCl. pyridine as a catalyst gave 3-(5-bromothiphene-2yl)-1-phenyl-1H-pyrazole derivatives. The synthesized compounds have been characterized by their melting point, TLC, IR and 1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B.subtillis & B.pumilus and Gram negative bacteria E. coli & P.vulgaris and antifungal against A.niger & p.crysogenium .