1-Methyl-3-(2-oxyethyl)-1H-Imidazol-3-ium-Borate Sulfonic Acid ([MOEI]-BSA) was easily prepared and used as a new and highly efficient solid acid catalyst for the synthesis of benzimidazole derivatives with high isolated yields. Various substituted benzimidazoles were synthesized by a combination of o-phenylenediamines and aldehydes in the presence of [MOEI]-BSA with excellent yields in water a...

3-Acylmethylidene-3,4-dihydroquinoxalin-2(1H)-ones are compounds which possess a wide range of physical and pharmaceutical applications. These compounds can be easily prepared by cyclocondensation of o-phenylenediamines and aroylpyruvates. Unsymmetrically substituted o-phenylenediamines can be obtained form regioisomeric mixtures of 3,4-dihydroquinoxalin-2(1H)-ones. It is often quite difficult ...

Hypervalent iodine(III)-induced oxidative [4+2] annulation of o-phenylenediamines and electron-deficient alkynes under metal-free conditions has been developed. The reaction allows for direct access to quinoxalines bearing two electron-withdrawing groups in an efficient manner.

Silica sulfuric acid is found to catalyze efficiently the condensation of o-phenylenediamines with various linear and cyclic ketones to afford the corresponding 1,5-benzodiazepines in quantitative yields under solvent-free conditions at room temperature

Vicinal bis(trifluoroacetimidoyl chloride)s, a novel kind of fluorinated building block, were obtained from o-phenylenediamines in the presence of TFA, triethylamine, triphenylphosphine and tetrachloromethane. Based on these blocks, a new synthesis involving [2 + 2 + 2] cycloaddition reactions for trifluoromethylated benzo-fused eight-membered rings was disclosed.

The design of polymers with repeating [C(NR2)2CH2CH2] units which may simultaneously provide conformational control and contain repeating electroactive centres is discussed; (NR2)2 groups would be ideally provided by ortho-phenylenediamine derivatives, with 1,8-diaminonaphthalenes as alternatives. Oligomers containing 1,8-bis(methylamino)naphthalenes, up to the hexamer, were obtained by condens...

The carcinogenicity of 23 phenylenediamines and related compounds was reviewed. An extensive analysis of the methods used indicated that the bioassays were conducted well. The data suggest that the carcinogenicity of 4-substituted 1,3-phenylenediamines is reduced substantially or eliminated completely by oxidation of one or both amine groups or by N-substitution. Oxidation of a methyl substitue...

silica sulfuric acid is found to catalyze efficiently the condensation of o-phenylenediamines with various linear and cyclic ketones to afford the corresponding 1,5-benzodiazepines in quantitative yields under solvent-free conditions at room temperature

Pyridobenzimidazoles 6a-iwere synthesized in very good to excellent yields (81-96%) by the condensation of substituted N-phenyl-o-phenylenediamines 4a-d with indole/benzo[b]thiophene-3-aldehydes 5a-t inmethoxyethanol under reflux conditions. The diamines 4a-d were prepared byfirst treating 2-chloro-3-nitropyridine (1)with suitably substituted anilines 2a-d then reducing the resulting3-nitro-N-p...

A simple and versatile method for the synthesis of 1,5-benzodiazepines is via condensation of o-phenylenediamines (OPDA) and ketones in the presence of catalytic amount of H-MCM-22 using acetonitrile as solvent at room temperature. In all the cases, the reactions are highly selective and are completed within 1-3 h. The method is applicable to both cyclic and acyclic ketones without significant ...