Michael addition of active methylene compounds to (Z)-2-arylidenebenzo[b]thiophen-3(2H)-ones

A series of 2-amino-4-aryl-4 H -1-benzothieno[3,2- b ]pyran-3-carboxylates and 2-amino-4-aryl-3-cyano-4H-1-benzothieno[3,2- b ]pyrans has been synthesized through Michael addition of ( Z )-2-arylidenebenzo[ b ]thiophen-3(2 H )-ones with active methylene compounds, such as ethyl cyanoacetate and malononitrile.  The reaction was carried out in ethanol, in the presence of piperidine as a basic catalyst.  The structures of the prepared compounds were determined by spectroscopic methods: 1 H-NMR, 13 C-NMR and confirmed by single crystal X-Ray diffraction.