H. M. El-Shaaer
Mar 31, 2012
Citations
0
Influential Citations
6
Citations
Journal
European Journal of Chemistry
Abstract
An efficient synthesis of 7-amino-9-hydroxy-6-oxo-6H-benzo[c]chromene-8-carbonitrile derivatives ( 2 , 6 ) and 4-methyl-2-oxo-2H-chromene-3-carbonitrile ( 5 ) via Claisen condensation of 2-hydroxyacetophenones ( 1 , 3 ) with ethyl cyanoacetate in the presence of sodium metal is reported. Reaction of 5 with thiosemicarbazide gave 1-(3-cyano-4-methyl-2-oxoquinolin-1(2 H )-yl)thiourea ( 7 ). Treatment of 5 with 6,8-dichloro-4-oxo-4 H -chromene-3-carboxaldehyde gave 4-(2-(6,8-dichloro-4-oxo-4 H -chromen-3-yl)-2-hydroxyethyl)-2-oxo-2 H -chromene-3-carbonitrile ( 9 ). Further treatment of 5 with ethyl acetate followed by condensation with 6,8-dichloro-3-formylchromone gave 7-((6,8-dichloro-4-oxo-4 H -chromen-3-yl)methyleneamino)-9-hydroxy-6H-benzo[ c ]chromen-6-one ( 12 ). Structures of the products were established on the basis of elemental analysis, IR, 1 H and 13 C NMR, mass spectra and semi-empirical AM1-MO calculations. The antimicrobial activities of the synthesized products were also studied.