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Acta Cryst. (2012). E68, o3417-o3418
[ doi:10.1107/S1600536812047307 ]

4-({(Z)-5-[(Z)-3-Ethoxy-4-hydroxybenzylidene]-3-methyl-4-oxo-1,3-thiazolidin-2-ylidene}amino)benzoic acid dimethylformamide monosolvate

P. Kosma, E. Selzer and K. Mereiter

Abstract: The molecular structure of the title compound, C₂₀H₁₈N₂O₅S·C₃H₇NO, represents an essentially planar 5-benzylidene-thiazolidine moiety (r.m.s. deviation from planarity without ring substituents = 0.095 Å) to which the 4-aminobenzoic acid fragment is inclined at 76.23 (1)°. In the crystal, the benzoic acid molecules are arranged in layers parallel to [001] which are built up from inversion dimers held together by head-to-tail phenol-carboxy O-HO hydrogen bonds and head-to-tail [pi] - [pi] stacking interactions between the 5-benzylidene-thiazolidine moieties (ring centroid distance = 3.579 Å). These layers are separated by the dimethylformamide solvent molecules which are firmly anchored via a short O-HO hydrogen bond [OO = 2.5529 (10) Å] donated by the -COOH group.