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

Abstract

A series of 2-amino-4-aryl-4H-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(2H)-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.