Experimental

R factor = 0.041; wR factor = 0.118; data-to-parameter ratio = 15.0. In the title compound, C19H17NO4S, the phenyl ring and the naphthalene ring system are oriented at a dihedral angle of 4.12 (2) and the molecule adopts a U-shaped conformation. The Cc—C—N—S (c = carboxy) torsion angle is 90.98 (15) In the crystal, molecules are linked by O—H O and N— H O hydrogen bonds, resulting in (100) chains incorporating centrosymmetric R22(14) and R 2 2(10) loops. Weak aromatic – stacking is also observed [centroid–centroid separations = 3.963 (2) and 3.932 (2) Å]. Related literature For the synthesis and related structures, see: Arshad et al