There is an association between occupational exposure to hair dyes and incidence of cancers. Permanent oxidant hair dyes are consisted of many chemical components including ortho-phenylenediamines. To clarify the mechanism of carcinogenesis by hair dyes, we examined DNA damage induced by mutagenic ortho-phenylenediamine (o-PD) and its derivatives, 4-chloro-ortho-phenylenediamine (Cl-PD) and 4-n...

The synthesis of some fluorescent coumarin dyes derived from coumarin-3-carboxylic acid were described.The new dyes are obtained by condensation of coumarin – 3 carboxylic acid derivatives with para substituted ortho phenylenediamines and cyclisation of the mono condensed ortho phenylenediamines in an acid medium. The obtained dyes were characterized from their physico-chemical point of view by...

The ability of the electron transport particulate fraction of Azotobacter vinelandii strain O to oxidize tetramethyl-p-phenylenediamine (TMPD) and p-phenylenediamine (PPD) was examined in detail. The highest specific activity for TMPD and PPD oxidation concentrated in the A. vinelandii O R(3) fraction. The A. vinelandii O R(3) fraction was used to develop a standard manometric assay which gave ...

While elemental sulfur has been largely used as oxidant or sulfurating agent, its role a catalyst not developed. We report here catalytic activity in the oxidative condensation of o-phenylenediamines with acetophenones DMSO to provide quinoxalines. The method was also extended α-tetralones, propiophenones (R=Me) well higher homologues (R=Et, n-Pr) place acetophenones, leading wide range naphtho...

A simple, highly efficient and green procedure for the condensation of o-phenylenediamines with 1, 2-dicarbonyl compounds in the presence of vitamin C, as an inexpensive organocatalyst, is described. Using this method, variety of quinoxaline derivatives with different electron releasing and electron withdrawing substituents, are produced in high to excellent yields at room temperature in ethano...

A novel series of hybrid molecules 4a-i and 5a-i were prepared by condensation of 4-(trimethylsilylethynyl)benzaldehyde 1 with substituted o-phenylenediamines. These in turn were reacted with 2-(azidomethoxy)ethyl acetate in a Cu alkyne-azide cycloaddition (CuAAC) to generate the 1,2,3-triazole pharmacophore under microwave assistance. The newly synthesized compounds were examined for their in ...

BACKGROUND 1, 5-Benzodiazepines have been investigated extensively by organic chemists due to their medicinal and pharmacological properties. These compounds are synthesized by condensation of o-phenylenediamines with carbonyl compounds in the presence of acid catalysts. OBJECTIVES During our studies on the application of silica resin with acid functional moieties, we found that SiO2/H2SO4 mi...

A simple, highly efficient and green procedure for the condensation of o-phenylenediamines with 1, 2-dicarbonyl compounds in the presence of vitamin C, as an inexpensive organocatalyst, is described. Using this method, variety of quinoxaline derivatives with different electron releasing and electron withdrawing substituents, are produced in high to excellent yields at room temperature in ethano...

The synthesis of 8-aminoquinolines and 1,10-phenanthrolines with substituents in α of the nitrogen has been performed through an inverse-demanding aza-Diels-Alder (Povarov reaction) in the fluoroalcohols TFE or HFIP. This path involves simple starting materials: 1,2-phenylenediamines, enol ethers and aldehydes.