о-дианизидина

Химические свойства

o-Dianisidine, crystallizes dimorphically, rarely in needles, with mp 133°C , often in flakes with mp 137-138°C . It forms colorless crystals, but commercial products have a tinge of violet. It is sparingly soluble in water but soluble in alcohol, ether, and benzene. One gram of ethyl acetate dissolves 0.285 g of o-dianisidine at 73°C .

The pure compound is stable upon exposure to air, but commercial products turn violet. o-Dianisidine is resistant to water but sensitive to oxidizing agents.

Использование

o-Dianisidine is a starting material for the production of disazo dyes and pigments.
Like benzidine and o-tolidine, o-dianisidine forms colors with numerous oxidizing agents, e.g., copper, cobalt, and gold ions. o-Dianisidine is quantitatively determined by titration with nitrite using potassium iodide and starch paper as the indicator. o-Dianisidine can be detected in the urine using potassium 1,2-naphthoquinone4-sulfonate after extraction. A rapid and easy method is based on the color formed with cyanogen bromide. Its detection limit is 0.05 mg/kg.
The free o-dianisidine base and the dihydrochloride are marketed in moist forms with a 10-30% water content.

Подготовка

2-Nitroanisole is reduced (H2-catalyst or iron-formic acid) to o-anisidine or (benzidine-type reaction) to o-dianisidine [119-90-4], both of which are important as dye intermediates.

Общее описание

Colorless crystals or a light brown powder. Turns violet on standing. Carcinogen.

Реакции воздуха и воды

Finely powdered material is a significant dust explosion hazard. Insoluble in water.

Профиль реактивности

o-Dianisidine is a weak base. Reacts exothermically with acids. Sensitive to heat, air and prolonged exposure to light.

Пожароопасность

o-Dianisidine is combustible.

Токсикология

In the presence of rat liver homogenate, o- dianisidine is positive in the Ames test. It is capable of inducing unscheduled DNA synthesis inHeLa cells and in primary rat hepatocytes, and it provokes cell transformation in baby hamster kidney cells in vitro. o-Dianisidine is carcinogenic in rats. An oral dose of 30 mg administered three times per week for 13 months produced tumors in the zymbal glands and in other tissues. No conclusive epidemiological studies have been reported on the carcinogenicity of o-diani- sidine in humans. No MAK value has been established. o-Dianisidine is classified in group III B.

Профиль безопасности

Confirmed carcinogen with experimental tumorigenic data. Moderately toxic by ingestion. Mutation data reported. Combustible when exposed to heat or flame. When heated to decomposition it emits toxic fumes of NOx.

Канцерогенность

o-Dianisidine is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.