Substituent effects on hydrogen bonding of aromatic amide-carboxylate.

N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using (1)H NMR, (13)C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in a centrosymmetric R2(2)(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3.