5-Carboxy-N-phenyl-2-1H-Pyridone-d5;1,6-Dihydro-6-oxo-1-phenyl-3-pyridinecarboxylic Acid-d5; 6-Oxo-1-phenyl-1,6-dihydropyridine-3-carboxylic Acid-d5;5-Carboxy Pirfenidone-d5,
5-Carboxy-N-phenyl-2-1H-Pyridone-d5;1,6-Dihydro-6-oxo-1-phenyl-3-pyridinecarboxylic Acid-d5; 6-Oxo-1-phenyl-1,6-dihydropyridine-3-carboxylic Acid-d5;5-Carboxy Pirfenidone-d5,