F. Havaldar, S. Bhise, S. Burudkar
2004
Citations
0
Influential Citations
11
Citations
Journal
Journal of The Serbian Chemical Society
Abstract
Methoxy-5-nitrobenzaldehyde undergoes Knoevenagel reaction with malonic acid to give 3-methoxy-5-nitrocinnamic acid (I). Treatment of I with thionyl chloride yielded 3-chloro-5-methoxy-7-nitrobenzo(b)thiophene-2-carbonyl chloride (II )i n 45 % yield. The reaction of II with 2-nitrophenol in benzene gave 2-nitrophenyl 3-chloro-5-me- thoxy-7-nitrobenzo(b)thiophene-2-carboxylate (IIIa) in 65 % yield. Finally, dehydrochlo- rinative photocyclization of IIIa in acetone in the presence of the base triethylamine af- forded 10-methoxy-4,8-dinitro-6H-benzothieno2,3-cchromen-6-one (IVa). Thus, a series of derivatives IVa-i were synthesized in excellent yields. The structures of the obtained products were characterized by IR and 1 H-NMR spectroscopy, as well as elemental analy- sis. Their purity was ascertained by chromatographic analysis. All the compounds were tested for their antibacterial activity against S. aureus, E. coli, B. subtilis and S. typhosa.