2-((2,4-Dimethylphenyl)amino)nicotinic acid;2-[(2,4-Dimethylphenyl)amino]-3-pyridinecarboxylic acid ; 2-(2,4-dimethylanilino)nicotinic acid ; 2-(2,4-Dimethylanilino)pyridine-3-carboxylic acid ; 2-(2,4-dimethylanilino)pyridine-3-carboxylic acid