N-(2,5-Dichloro-phen-yl)succinamic acid.

In the title compound, C(10)H(9)Cl(2)NO(3), the conformation of the N-H bond in the amide segment is syn with respect to the ortho-Cl atom and anti to the meta-Cl atom of the benzene ring. In the crystal, inter-molecular O-H⋯O and N-H⋯O hydrogen bonds pack the mol-ecules into two types of chains along the a and b axes, respectively, leading to an overall sheet structure. The acid group in the side chain is disordered and was refined using a split model with site-occupation factors of 0.

N-(3-Chloro-phen-yl)-N'-(3-methyl-phen-yl)succinamide.

The asymmetric unit of the title compound, C(17)H(17)ClN(2)O(2), contains one half-mol-ecule with a center of inversion at the mid-point of the central C-C bond. The amide N-H group is anti to the meta-chloro/methyl groups in the adjacent benzene rings. The dihedral angle between the benzene ring and the NH-C(O)-CH(2) segment is 43.

N-(3-Chloro-phen-yl)succinimide.

In the title compound, C(10)H(8)ClNO(2), the chloro-benzene and the essentially planar (r.m.s.

N-(2,6-Dichloro-phen-yl)succinamic acid.

In the crystal of the title compound, C(10)H(9)Cl(2)NO(3), the conformations of the amide O atom and the carbonyl O atom of the acid segment are anti to each other and to the H atoms on the adjacent -CH(2) groups. The C=O and O-H bonds of the acid group are syn to one another. In the crystal, mol-ecules are packed into infinite chains through inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

N-(2,5-Dimethyl-phen-yl)succinamic acid monohydrate.

In the title compound, C(12)H(15)NO(3)·H(2)O, the conformation of the N-H bond in the amide segment is syn to the ortho-methyl group and anti to the meta-methyl group in the benzene ring. Further, the conformations of the amide O and the carbonyl O atom of the acid segment are anti to the adjacent methyl-ene H atoms. The C=O and O-H bonds of the acid group are syn to one another.