J. Kožíšek

N-(2,4,6-Trimethyl­phen­yl)maleamic acid

The molecular structure of the title compound, C13H15NO3, is stabilized by a short intramolecular O—H⋯O hydrogen bond within the maleamic unit. In the crystal, intermolecular N—H⋯O hydrogen bonds link molecules into zigzag chains propagating in [010].

2-Chloro-N-phenyl-acetamide.

In the title compound, C8H8ClNO, the conformations of the N—H and C=O bonds are anti to each other, but the C—Cl and C=O bonds in the side chain are syn. The molecules are linked by N—H⋯O hydrogen bonds into infinite chains running in the [101] direction.

N-(2-Methyl-phen-yl)maleamic acid.

In the title compound, C11H11NO3, the conformation of the N—H bond is anti to the C=O bond in the amide segment, while it is syn to the ortho-methyl group in the phenyl ring. In the maleamic acid unit, the amide C=O bond is anti to the adjacent C—H bond, while the carboxyl C=O bond is syn to the adjacent C—H bond. The C=O and O—H bonds of the acid group are in the relatively rare anti position to each other. This is an obvious consequence of the intramolecular O—H⋯O hydrogen bond donated to the amide carbonyl group. The ortho-substituted phenyl ring makes a dihedral angle of 12.7u2005(1)° with the mean plane of the maleamic acid unit. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules into zigzag chains parallel to [001]. These chains are further linked into sheet by weak π–π interactions [centroid–centroid distance = 3.425u2005(2)u2005Å].

N,N′-Diphenyl­suberamide

In the title compound (systematic name: N,N′-diphenyloctanediamide), C20H24N2O2, the two phenyl rings make an interplanar angle of 76.5u2005(2)°. The crystal structure is stabilized by intermolecular N—H⋯O hydrogen bonds, which link the molecules into chains running along the b axis. The crystal studied was non-merohedrally twinned, the fractional contribution of the minor twin component being 0.203u2005(2).

4-Chloro-N-(2,3-dimethyl­phen­yl)benzamide

The conformations of the N—H and C=O bonds in the structure of the title compound (N26DMP4CBA), C15H14ClNO, are anti to each other, similar to that observed in N-phenylbenzamide, N-(3,4-dimethylphenyl)benzamide, N-(2,6-dichlorophenyl)benzamide and other benzanilides. There are three molecules in the asymmetric unit of N26DMP4CBA. The central amide group is tilted with respect to the benzoyl ring by 45.2u2005(1)° in molecule 1, 21.2u2005(2)° in molecule 2 and 14.9u2005(2)° in molecule 3. The dihedral angles between the benzoyl and aniline rings are 39.9u2005(1), 51.0u2005(1) and 86.3u2005(3)° in molecules 1, 2 and 3, respectively. Intermolecular N—H⋯O hydrogen bonds link the molecules into infinite chains running along the [101] direction. One xylyl group is disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.

N-(4-Meth­oxy­phen­yl)maleamic acid

In the title compound, C11H11NO4, the asymmetric unit contains two unique molecules, both of which are almost planar, with r.m.s. deviations of 0.047 and 0.059u2005Å. The dihedral angles between the benzene ring and the plane of maleamic acid unit are 3.43u2005(5) and 5.79u2005(3)° in the two molecules. The molecular structures are stabilized by a short intramolecular O—H⋯O hydrogen bond within each maleamic acid unit. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into zigzag chains extending along [10]. Weak intermolecular C—H⋯O hydrogen bonds also exist.

N-(4-Chloro­phen­yl)benzamide

The structure of the title compound, C13H10ClNO, resembles those of N-phenylbenzamide, N-(2-chlorophenyl)benzamide and other benzanilides, with similar bond parameters. The amide group –NHCO– makes a dihedral angle of 29.95u2005(9)° with the benzoyl ring, while the benzoyl and aniline rings form a dihedral angle of 60.76u2005(3)°. The structure shows both intra- and intermolecular hydrogen bonding. The molecules are linked by N—H⋯O hydrogen bonds into chains running along the [100] direction.

4-Chloro-N-phenyl-benzamide.

In the title compound, C13H10ClNO, the dihedral angle between the two benzene rings is 59.6u2005(1)°. The crystal structure features N—H⋯O hydrogen bonds, which link the molecules into C(4) chains running along the a axis.

N,N'-Bis(2-chloro-phen-yl)propane-diamide.

The crystal structure of the title compound, C15H12Cl2N2O2, contains three intramolecular hydrogen bonds; two C—H⋯O and a nonclassical N—H⋯Cl. The structure is further stabilized by intermolecular N—H⋯O hydrogen bonds and C—H⋯π interactions, resulting in a three-dimensional network. The two benzene rings make an interplanar angle of 58.0u2005(1)°.

N-(3-Chloro-phen-yl)maleamic acid.

In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H⋯O hydrogen bond within the maleamic acid unit and the second is a C—H⋯O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044u2005Å, and makes a dihedral angle of 15.2u2005(1)° with the phenyl ring. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into C(7) chains running [010].