An elegant synthetic route to 3-cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-α]carbazoles

2-Benzylidene-1-oxo-1,2,3,4-tetrahydrocarbazoles (1a-e) obtained from the corresponding 1-oxo-1,2,3,4-tetrahydrocarbazoles on reaction with malononitrile in dry benzene with sodium hydride afforded 3-cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles (2a-e) in good yields. A plausible mechanism for the formation of the title compound has been proposed and all the compounds were characterised by IR, NMR, mass spectral methods and elemental analysis.