Antibacterial Activity of some New substitued 4‐(2‐Benzothiazolylamino‐2H[1]‐Pyran‐2‐ones

Abstract

Some new substitued 4‐(2‐benzithiazolylamino‐2H[1]‐pyran‐2‐ones are synthesized by condensation of 2H[1}‐pyran‐2‐ones and corresponding 2‐aminobenzothiazoles. Condensation of 4‐chloro‐6‐methyl‐2H[1]‐pyran‐2‐one 2 and 2‐aminobenzothiazoles 3(a‐c) gave corresponding 4‐(2‐benzothiazolylamino)‐6‐methyl‐2H[1]‐pyran‐2‐ones 4(a‐c). By condensation of 4‐chloro‐3‐nitro‐6‐methyl‐2H[1]‐pyran‐2‐one 6a and 2‐aminobenzothiazoles 3(ad) were synthesized 4‐(2‐benzothiazolylamino)‐3‐nitro‐6‐methyl‐2H[1]‐pyran‐2‐one 6a and 4‐(6‐ethoxy‐2‐benzothiazolylamino)‐3‐nitro‐6‐methyl‐2H[1]‐pyran‐2‐one 6c . The antibacterial activity of products 4(a‐d) against E. coli S. aureus and Clebsiella were investigated. Compounds 4(a‐d) showed light bactericide activity against E. coli, S. aureus and Clebsiella. Compounds 4b and 6d were more active against E. coli. Emphatic activity against S. aureus exhibited compounds 4c and 6d whereas compounds 6a and 6d exhibited the strongest activity against Clebsiella. In general there was a direct positive correlation between increasing concentration of the compound and antibacterial activity.