Synthesis, characterization and DFT study of 4H-benzo[h]chromene derivatives

Interaction of 4-methoxy-1-naphthol (1) with alpha-cyano-p-chlorocinnamonitrile (2a) and ethyl alpha-cyano-p-chlorocinnamate (2b) provided 2-amino-4-(4-chlorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carbonitrile (3a) and ethyl 2-amino-4-(4-chlorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carboxylate (3b), respectively. Structures of these compounds were established on the basis of IR, UV, H-1 NMR, C-13 NMR, C-13 NMR-DEPT and MS data. Moreover, imino tautomer (3b') has been designed. Using density functional theory geometries have been optimized at B3LYP/6-31G* level of theory, the absorption spectra has been computed by using time dependant density functional theory at TD-B3LYP/6-31G* level of theory. Moreover, the absorption spectra in solvents have been computed and compared with experimental data. The highest occupied molecular orbitals, lowest unoccupied molecular orbitals and HOMO-LUMO energy gap of studied systems have been discussed. (C) 2012 Elsevier B.V. All rights reserved.