Synthesis and antimicrobial activity of some new 3-chloro-6-substituted-N-(substituted 2H-[1,3]oxazino[6,5-b]quinolin-3-(4H,5aH,9aH)-yl) benzo[b]thiophene-2-carboxamides

Abstract

(E)-3-Chloro-N'-((6-substituted-2-hydroxy quinolin-3-yl) methylene)-6-substituted benzo[b]thiophene-2-carbohydrazides 3a-d obtained by the reaction of 3-chloro-6-substituted benzo[b]thiophene-2-carbohydrazides 1a and 1b and 6-substituted-2-hydroxy quinoline-3-carboxaldehyde 2a and 2b, on reduction with sodium borohydride gives the respective 3-chloro-N'-((6-substituted-2-hydroxy quinolin-3-yl) methyl)-6-substituted benzo[b]thiophene-2-carbohydrazides 4a-d. These on further reaction with formalin yield 3-chloro-6-substituted-N- (6-substituted 2H-[1,3]oxazino[6,5-b]quinolin-3-(4H,5aH,9aH)-yl)benzo[b]thiophene-2-carboxamides 5a-d. The structures of all the newly synthesized compounds have been confirmed by IR, H-1 NMR and mass spectral data. All these compounds have been screened for their antibacterial activity against Gram (+ve) S. aureus and B. subtilus, Gram (-ve) E. coli and K. pneumonia and antifungal activity against A. niger and C. albi cans.