N-(4-Methyl-2-nitro­phen­yl)succinamic acid

In the title compound, C(11)H(12)N(2)O(5), the conformation of the N-H bond in the amide segment is syn to the ortho-nitro group in the benzene ring. The amide C=O and the carboxyl C=O of the acid segment are syn to each other and both are anti to the H atoms on the adjacent -CH(2) groups. Furthermore, the C=O and O-H bonds of the acid group are in syn positions with respect to each other. The dihedral angle between the benzene ring and the amide group is 36.1 (1)°. The amide H atom shows bifurcated intra-molecular hydrogen bonding with an O atom of the ortho-nitro group and an inter-molecular hydrogen bond with the carbonyl O atom of another mol-ecule. In the crystal, the N-H⋯O(C) hydrogen bonds generate a chain running along the [100] direction. Inversion dimers are formed via a pair of O-H⋯O(C) interactions, that form an eight-membered hydrogen-bonded ring involving the carboxyl group.