Abstract
Ethyl esters of 2-cyano-3-arylacrylic acid 1a–d (a = 4-CH3-C6H4-, b = 4-N(CH3)2-C6H4-, c = 2-CH3O-C6H4-, d = 2-Cl-C6H4-) reacted with 5,5-dimethyl-1,3-cyclohexanedione (2p, Y=CH3), and 1e–g (e = 4-CH3-C6H4-, f = 2-CH3O-C6H4-, g = 2-Cl-C6H4-) reacted with 1,3-cyclohexanedione (2q, Y=H) in the presence of alcoholic sodium ethoxide to give the corresponding ethyl esters of 2-amino-7,7-dimethyl-5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromene-3-carboxylic acid 4a–d and 2-amino-5-oxo-4-aryl-5,6,7,8-tetrahydro-4H-chromene-3-carboxylic acid 4e–g. The structures of the compounds 4a–g were confirmed by their ultraviolet, infrared, 1H NMR, 13C NMR, and mass spectral data and elemental analyses.
ACKNOWLEDGMENT
We are pleased to acknowledge Teruo Shinmyozu, Institute for Materials Chemistry and Engineering, Kyushu University, Japan, for the mass spectrum, NMR, and elemental analyses.