Cyclization of 4,5-Diamino Pyrazole Derivatives and Their Antibacterial Activities

A convenient synthesis of intermediate 4,5-diamino-3-aryl-l-phenylpyrazoles 4a--4c was reported. The different cyclization reactions were carried out with chalcone, 2-mercaptoacetic acid and p-anisialdehyde, ethyl chloroformate, glyoxal and thiourea to afford different N and S containing heterocycles. The reaction conditions were compared by conventional heating and microwave irradiation. The structures of the cyclization products were de- termined by analytical and spectroscopic data. All the synthesized compounds were screened for antibacterial activities in vitro.