Experimental

R factor = 0.041; wR factor = 0.108; data-to-parameter ratio = 14.9. In the title compound, C13H12N2O4S, the dihedral angle between the benzene rings is 73.64 (7). The amide H atom exhibits bifurcated hydrogen bonding: an intramolecular N— H O hydrogen bond generates an S(7) motif while in the crystal, N—H O(S) hydrogen bonds link the molecules into zigzag C(4) chains running along the b axis. Related literature For studies on the effects of substituents on the structures and other aspects of N-(aryl)-amides, see: Alkan et al. (2011); Bowes et al. (2003); Gowda et al. (2000); Saeed et al. (2010)