ABSTRACT3-Chlorobenzothiophene-2-carbonyl chloride 1 was reacted with 4-aminoacetophenone in acetone to give compound 2. In order to prepare chalcones 3a-d, compound 2 was condensed with various aldehydes in the presence of KOH in DMF. These chalcones 3a-d on cyclization with urea, thiourea, hydroxylamine hydrochloride, phenyl hydrazines and hydrazine hydrate gave the corresponding oxapyrimidines 4a-d, isoxazolines 5a-d, pyrazoles 6a-h, pyrazolines 7a-d and thiopyrimidines 8a-d, respectively. The structures of all the synthesized compounds were confirmed by spectral data and had been screened for antibacterial activity.