4-Chloro-N-(2-chloro-phen-yl)benzamide

In the mol-ecular structure of the title compound, C(13)H(9)Cl(2)NO, the amide N-C=O plane makes dihedral angles of 31.53 (8) and 36.23 (8)°, respectively, with the 4-chloro- and 2-chloro-phenyl rings. The dihedral angle between the two benzene rings is 6.25 (8)°. The mol-ecules are stacked in columns along the b axis through inter-molecular N-H⋯O hydrogen bonds. The columns are further connected by weak C-H⋯O hydrogen bonds. The compound is not isomorphous with the fluoro analogue.

N-(4-Chloro-phen-yl)-3,4,5-trimethoxy-benzamide

In the title compound, C₁₆H₁₆ClNO₄, the dihedral angle between the two aromatic rings is 67.33 (8)°. The crystal packing shows strong inter­molecular N—H⋯O hydrogen bonds that link the mol­ecules to form chains along [01].

2,4-Dichloro-N-cyclo-hexyl-benzamide

In the title mol­ecule, C₁₃H₁₅Cl₂NO, the cyclohexane ring adopts a chair conformation. The aromatic ring plane is oriented with respect to the N/O/C plane at a dihedral angle of 51.88 (7)°. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into infinite chains along the [010] direction.

N-(2-Methoxyphenyl)-2-nitrobenzamide

Geometric parameters of the title compound, C₁₄H₁₂N₂O₄, are in the usual ranges. The dihedral angle between the two aromatic rings is 28.9 (1)°. The nitro group is twisted by 40.2 (1)° out of the plane of the aromatic ring to which it is attached. The crystal structure is stabilized by an N—H⋯O hydrogen bond.

N-(2-Chloro-4-nitro-phen-yl)-2-nitro-benzamide

In the title compound, C₁₃H₈ClN₃O₅, the dihedral angle between the two aromatic rings is 70.74 (6)°. The nitro groups of the Cl-substituted and benzamide benzene rings are twisted by 2.6 (1) and 31.3 (2)°, respectively. The crystal packing shows inter­molecular C—H⋯O hydrogen bonds that link mol­ecules into sheets stacked along [010].

N-(2-Methyl-phen-yl)-2-nitro-benzamide

In the title compound, C₁₄H₁₂N₂O₃, the dihedral angle between the two aromatic rings is 41.48 (5)°. The nitro group is twisted by 24.7 (3)° out of the plane of the aromatic ring to which it is attached. The mol­ecules are connected by N—H⋯O hydrogen bonds into chains running along the a axis.

Practical synthesis of potential endothelin receptor antagonists of 1,4-benzodiazepine-2,5-dione derivatives bearing substituents at the C3-, N1- and N4-positions

The expedient synthesis of various 1,4-benzodiazepine-2,5-dione compounds, particularly those having substituents at the C3-, N1- and N4-positions is achieved. The important features in these synthetic strategies include: (i) using the coupling reaction of isatoic anhydride with alpha-amino ester for direct construction of the core structure of 1,4-benzodiazepine-2,5-dione; (ii) using potassium carbonate as the base of choice for selective alkylation at the N1-site, while using lithiated 2-ethylacetanilide as the required base to furnish the N4-alkylation; and (iii) using 2-nitrobenzoyl chloride as a synthetic equivalent of anthranilic acid to facilitate the polyethylene resin-bound liquid-phase combinatorial synthesis. The prepared 1,4-benzodiazepine-2,5-dione compounds are evaluated for endothelin receptor antagonism by a functional assay that measures the inhibitory activity against the change of intramolecular calcium ion concentration induced by endothelin-1. The preliminary results indicate that 1,4-benzodiazepine-2,5-diones bearing two flanked aryl substituents at the N1- and N4-sites show better inhibitory activity than the corresponding unalkylated and N-monoalkylated compounds. A promising candidate, 1-benzyl-7-chloro-3-isopropyl-4-(3-methoxybenzyl)-1,4-benzodiazepine-2,5-dione (17b), exhibits an IC50 value in low nM range.