The title compound, C(17)H(16)N(2)O(6), is a decomposition product of the hypertension drug nifedipine [systematic name: dimethyl 2,6-dimethyl-4-(2-nitro-phen-yl)-1,4-dihydro-pyridine-3,5-dicarboxyl-ate]. The dihedral angle between the nitro-sophenyl ring and the pyridine ring is 67.1 (5)°.