3-Chloro-1-benzothiophene-2-carbonyl chloride 1 was reacted with glycine in acetone to give 3-chloro-1-benzothiophen-2-yl-carbonylaminoacetic acid 2. Various aldehydes on treatment with compound 2 in acetic anhydride to gave 1,3-oxazol-5-ones 3a-d. These oxazolones was treated with aromatic amines or hydrazides to get various imidazol-4-ones 4a-t or 5a-l. Oxazolones 3a-d was also treated with aromatic hydrazines, expansion of five member oxazole ring to six member triazine ring occurs to yield 1,2,4-triazin-6-ones 6a-h. The structures of all the synthesized compounds were confirmed by spectral data and had been screened for antibacterial activity.