One pot synthesis of 2-amino-5-oxo-4-aryl-5 , 6 , 7 , 8-tetrahydro-4 H-chromenes-3-carboxilic acid ethyl esters

Ethyl esters of 2-cyano-3-arylacrylic acid 1a-b ( a = 3BrC 6 H 4 , b= 4OHC 6 H 4 ) reacted with 5, 5-dimethyl-1, 3-cyclohexane (2b, R = CH 3 ) and 1c-d (c= 3OHC 6 H 4 , d= 3NO 2 C 6 H 4 ) reacted with 1, 3-cyclohexanedione (2a, R = H) and 5, 5-dimethyl-1, 3-cyclohexanedione (2b, R=CH3) in the presence of alcoholic sodium ethoxide to give the corresponding ethyl esters of 2amino7, 7dimethyl-5-oxo-4-aryl-5, 6, 7, 8-tetrahydro4Hchromenes-3-carboxylic acid 3a-c, 3f and 2amino-5-oxo-4-aryl-5, 6, 7, 8-tetrahydro4Hchromenes-3-carboxilic acid ethyl esters 3d-e. The structures of the compounds 3a-f were confirmed by their ultraviolet (UV), infrared (IR), 1H NMR, 13C NMR, mass spectra and elemental analyses.