5 H -1-Benzothiopyrano[2,3- b ]pyridin-5-one

Molecules of the title compound, C 12 H 7 NOS, with one half-molecule in the asymmetric unit, are disordered about a crystallographic centre of inversion. Refinement showed that the C=O group is disordered with the S atom and the N atom is disordered over four positions. Adjacent molecules are connected through C—H...O hydrogen bonds and π...π interactions (centroid–centroid distances of 3.635 and 3.858 Å).