3-pyridinecarboxylic acid, 1,2-dihydro-6-methyl-2-oxo- 6-methyl-2-oxo-1,2-dihydropyridine-3-carboxylic acid InChI=1/C7H7NO3/c1-4-2-3-5(7(10)11)6(9)8-4/h2-3H,1H3,(H,8,9)(H,10,11