In the crystal structure of the title compound, C5H3NO3S, determined at 100 K, the nitro group and the aldehyde group make angles of 8.37 (16) and 8.5 (4)degrees, respectively, with the plane of the thiophene ring.
The title compound, C8H9NO3, was synthesized from 4-nitrophenol and ethyl iodide via the Williamson ether synthesis. The crystal structure has been determined at 100 K.