ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, vol.66, 2010 (SCI-Expanded)
In the title compound, C(16)H(11)NO(4)S, the nine-membered fused ring is nearly planar, with maximum deviations from the mean plane of -0.022 (1) angstrom for the N atom and 0.011 (1) angstrom for the S atom, and makes a dihedral angle of 53.56 (7)degrees with the phenyl ring. The crystal structure is stabilized by O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen-bonding interactions.