Open AccessA facile synthesis of 10-methoxy-4. 8-dinitro-6H-benzo [2,3-c]chromen-6-one
Author(s) -
Freddy H. Havaldar,
Sanjay Bhise,
Sandeep Burudkar
Publication year - 2004
Publication title -
journal of the serbian chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.227
H-Index - 45
eISSN - 1820-7421
pISSN - 0352-5139
DOI - 10.2298/jsc0407527h
Subject(s) - chemistry , thionyl chloride , triethylamine , yield (engineering) , knoevenagel condensation , thiophene , medicinal chemistry , base (topology) , chloride , acetone , benzene , organic chemistry , nuclear chemistry , catalysis , mathematical analysis , materials science , mathematics , metallurgy
3-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) in 45 % yield. The reaction of II with 2-nitrophenol in benzene gave 2-nitrophenyl 3-chloro-5-methoxy- 7-nitrobenzo[b]thiophene-2-carboxylate (IIIa) in 65 % yield. Finally, dehydrochlorinative photocyclization of IIIa in acetone in the presence of the base triethylamine afforded 10-methoxy-4,8-dinitro-6H-benzothieno_2,3-c_chromen-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 1H-NMR spectroscopy, as well as elemental analysis. 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.