Ethyl 2-amino-4-phenyl-4H-1-benzothieno[3,2-b]pyran-3-carboxylate

Abstract

The title heterocyclic compound, C20H17NO3S, was synthesized by condensation of ethyl cyanoacetate with (Z)-2-benzylidenebenzo[b]thiophen-3(2H)-one in the presence of a basic catalyst in ethanol. The phenyl and ester groups make dihedral angles of 77.67 (6) and 8.52 (6)°, respectively, with the benzothienopyran ring system [maximum r.m.s. deviation = 0.1177 (13) Å]. In the crystal, centrosymmetric dimers are formed through pairs of N—H...O hydrogen bonds between the amine and ester groups. Intermolecular C—H...N hydrogen bonds and C—H...π interactions involving the thiophene ring are also observed.