Mohammed H. Al-Douh

2-Amino-N-(2-hydr-oxy-3-methoxy-benzyl-idene)aniline.

The reaction of o-vanillin 1 with o-phenylenediamine 2PD, in dichloromethane at low conditions produced novel amino benzeneamine: 2-amino-N-(2-hydroxy-3-methoxybenzylidene) aniline 2. Intermediate 2 is isolated and obtained as single crystals and the structure was determined and studied by x-ray crystallography. The complete assignments of 2 were made using FTIR, HRMS, 1D and 2D NMR including APT, COSY, HMQC and HMBC in CDCl3 and will be discussed.

Anti-Proliferation Effects of Benzimidazole Derivatives on HCT-116 Colon Cancer and MCF-7 Breast Cancer Cell Lines

Benzimidazoles 1-4 were obtained using modified synthesis methods and studied for their ability to inhibit cell proliferation of colon cancer cell HCT-116 and breast cancer cell MCF-7 using MTT assays. In the HCT-116 cell line, benzimidazole 2 was found to have an IC50 value of 16.2 ± 3.85 μg/mL and benzimidazole 1 a value of 28.5 ± 2.91 μg/mL, while that for benzimidazole 4 was 24.08 ± 0.31 μg/mL. In the MCF-7 cell line, benzimidazole 4 had an IC50 value of 8.86 ± 1.10 μg/mL, benzimidazole 2 a value of 30.29 ± 6.39 μg/mL, and benzimidazole 1 a value of 31.2 ± 4.49 μg/mL. Benzimidazole 3 exerted no cytotoxicity in either of the cell lines, with IC50 values >50 μg/mL. The results suggest that benzimidazoles derivatives may have chemotherapeutic potential for treatment of both colon and breast cancers.

6,6'-Dimeth-oxy-2,2'-[p-phenyl-ene-bis(nitrilo-methyl-idyne)]diphenol chloro-form disolvate.

The title compound, C22H20N2O4·2CHCl3, a new Schiff base compound, lies across a crystallographic inversion centre. An intramolecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. Intermolecular bifurcated C—H⋯O hydrogen bonds involving the two O atoms of the Schiff base ligand and the H atom of the chloroform solvent of crystallization, generate an R 2 1(5) ring motif. The crystal structure is stabilized by intermolecular C—H⋯π and π–π interactions [centroid to centroid distance = 3.6158 (10) Å]. In the crystal structure, molecules are stacked down the c axis.

2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol monohydrate.

The asymmetric unit of the title compound, C22H20N2O4·H2O, comprises a substituted benzimidazole molecule and a water molecule of crystallization. The dihedral angles between the benzimidazole ring system and the two outer benzene rings are 16.54 (4) and 86.13 (4)°. The dihedral angle between the two hydroxy-substituted benzene rings is 82.20 (5)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds, involving the hydroxy groups and water molecules, form R 4 4(8) ring motifs, and link symmetry-related molecules into extended chains along the c axis. The crystal structure is further stabilized by weak intermolecular C—H⋯O hydrogen bonds, weak C—H⋯π and π–π stacking [centroid–centroid = 3.6495 (6)–3.7130 (6) Å] interactions. Intramolecular O—H⋯O and O—H⋯N interactions are also present.

2-[1-(2-Hydr­oxy-3-methoxy­benz­yl)-1H-benzimidazol-2-yl]-6-methoxy­phenol methanol 1.13-solvate

In the main molecule of the title compound, C22H20N2O4·1.13CH4O, the dihedral angles between the benzimidazole plane and the two benzene rings are 80.53 (10) and 82.76 (10)°. The solvent molecules are disordered between three positions, with refined occupancies of 0.506 (13), 0.373 (13) and 0.249 (5). The crystal structure is stabilized by intermolecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds. The crystal studied was a merohedral twin [BASF ratio of 0.917 (1)/0.083 (1)].

(R)- and (S)-1-(2-(benzyloxy)-3-methoxyphenyl)-2,2,2-trichloroethyl benzenesulfonate

A novel chiral compound was synthesized from the reaction between the new benzimidazole, 2-(2-benzyloxy-3-methoxyphenyl)-1H-benzimidazole 8 and benzenesulfonyl chloride 9 in dry dichloromethane DCM at 45oC for 10 hr in the presence of 4-N,N-dimethyl aminopyridine DMAP 12 as a catalyst was expected to obtain 2-(2-benzyloxy-3-methoxyphenyl)-1-(phenylsulfonyl)-1Hbenzimidazole, 10. Unfortunately, a novel chiral compound (R) and (S) 1-(2-benzyloxy-3methoxyphenyl)-2,2,2-trichloroethyl benzenesulfonate 11 was obtained as a single crystal (59% yield) with melting point of 58.4°C. We suggest preliminary mechanisms of the formation of 11 by two ways: a) It is formed benzimidazolide ion 13 that is attacked from benzene sulfonic acid 15, which is hydrolyzed from 9 to form N-(2-aminophenyl)-2-(benzyloxy)-3-methoxybenzimidine benzenesulfonate 17, or b) that benzimidazole 8 is hydrolyzed to its basic compound benzyl o-vanillin 18, which it attacks the 4-(dimethylamino)-1-(phenylsulfonyloxy) pyridinium chloride 21 to form (2(benzyloxy)-3-methoxyphenyl) (phenylsulfonyloxy) methylium ion 22. However, the mechanism of this reaction still is under investigation.

Synthesis, NMR spectroscopy and crystal structures studies of 2-amino-N-(2-hydroxy-3-methoxybenzylidene) aniline

The reaction of o-vanillin 1 with o-phenylenediamine 2PD, in dichloromethane at low conditions produced novel amino benzeneamine: 2-amino-N-(2-hydroxy-3-methoxybenzylidene) aniline 2. Intermediate 2 is isolated and obtained as single crystals and the structure was determined and studied by x-ray crystallography. The complete assignments of 2 were made using FTIR, HRMS, 1D and 2D NMR including APT, COSY, HMQC and HMBC in CDCl 3 and will be discussed.

2-Amino-N-(2-benz­yloxy-3-methoxy­benzyl­idene)aniline

The title compound, C21H20N2O2, a Schiff base ligand, contains two independent molecules (A and B) in the asymmetric unit, with similar conformations. In molecule A, the central benzene ring forms dihedral angles of 30.79 (13) and 23.56 (13)°, respectively, with the amino and benzyl benzene rings, while in molecule B these angles are 32.30 (13) and 13.13 (12)°. The molecular structure is stabilized by intramolecular N—H⋯N and C—H⋯O hydrogen bonds. The crystal structure is stabilized by N—H⋯N hydrogen bonds and N—H⋯π and C—H⋯π interactions.