Cocrystals of chlorzoxazone with carboxylic acids

Two polymorphs of a chlorzoxazone:2,4-dihydroxybenzoic acid cocrystal and one form of a chlorzoxazone:4-hydroxybenzoic acid cocrystal are characterized and the crystal structure of chlorzoxazone:2,4-dihydroxybenzoic acid (form 1) is reported and analyzed, revealing an uncommon carbonyl–carbonyl interaction and a destabilizing C–H⋯Cl–C interaction.