1. Conditions favouring the condensation of o-phenylenediamine with alpha-oxo acids to form substituted quinoxalines have been investigated. The best yields (85-100%) are obtained by incubation of the reagents in 2m-hydrochloric acid. Substitution of acetic acid for hydrochloric acid, or of halogen-substituted 1,2-diaminobenzenes for phenylenediamine, increases the initial rate of reaction, but...

An efficient one-pot oxidation/condensation tandem process has been developed for the synthesis of 2-substituted benzimidazole derivatives from benzylic alcohols and 1,2-phenylenediamine with use of urea-hydrogen peroxide/silica phosphoric acid  as a bifunctional catalyst. This method provides a rapid and efficient access to 2-substituted benzimidazoles.

The Cosmetic Ingredient Review Expert Panel (CIR Panel) reviewed the safety of hydroxypropyl bis(N-Hydroxyethyl-p-Phenylenediamine) HCl, which functions as an oxidative hair dye ingredient. The Panel considered relevant animal and human data provided in this safety assessment and concluded that hydroxypropyl bis(N-hydroxyethyl-p-phenylenediamine) HCl is safe for use in oxidative hair dye formul...

BACKGROUND We report the synthesis of benzimidazoles using lanthanum chloride as an efficient catalyst. One-pot synthesis of 2-substituted benzimidazole derivatives from o-phenylenediamine and a variety of aldehydes were developed under mild reaction conditions. RESULTS We have examined the effect of different solvents using the same reaction conditions. The yield of the product varied with t...

Dermal exposure to chemicals is highly relevant in relation to the use of cosmetic products, both in consumers and in individuals exposed occupationally. Regulatory frameworks exist within the EU to limit the dermal exposure of the general population and workers to chemicals in general, as well as to limit the use of certain substances in cosmetic products. The objective of the study was to inv...

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...

Ferricyanide-containing liposomes were used as a system to compare the electron- and proton-translocating properties of six redox reagents commonly used as electron donors for biochemical systems. The effects of different ionophore combinations on the ferricyanide-reduction rate were generally consistent with the expected proton- and electron-translocating properties of the mediators. The trans...

In an innovative approach to push the boundaries of antimicrobial and antioxidant strategies, we present synthesis characterization a novel terpolymer derived from N-Phenyl-p-phenylenediamine 2-aminopyrimidine with formaldehyde in presence dimethylformamide as reaction medium through polycondensation technique. Leveraging this ligand, introduce intriguing terpolymer-metal complex, created Ni (I...

Optimum reaction conditions were evaluated for assay of serum ceruloplasmm by measurement of its p-phenylenediamine oxidase activity. The pH optima of p-phenylenediamine oxidase activities of human and rat ceruloplasmins were 5.45 and 5.2, respectively. The p-phenylenediamine oxidase activity of rat ceruloplasmin was markedly inhibited by phosphate (0.1 mol/Iiter), that of human ceruloplasmin o...