The 6-Cyano-5-oxo-7-(methylthio)-5H-thiazolo[3,2-a]pyrimidine (3) is prepared by condensing 2-amino thiazole (1) with ethyl 2-cyano-3,3-bis(methylthio)acrylate (2) in N,N-dimethyl formamide (DMF) and anhydrous potassium carbonate under reflux condition. The latter were further reacted with selected nucleophiles such as substituted aryl amines to afford 7-aryl amino derivatives of parent thiazolo[3,2-a]pyrimidine. The newly synthesized compounds were further screening of antibacterial activity.