Nitric Acid → 1-Aminoanthraquinone

Participants

Reaction Conditions

Reaction Steps

A 500 ml. electromagnetically stirred autoclave was charged with 5.0 g (0.0178 mole of 1-nitroanthraquinone) of 1-nitroanthraquinone (having a purity of 90% and containing 5% of 1,5-dinitroanthraquinone, 3% of 1,8-dinitroanthraquinone and 2% of 1,6- and 1,7-dinitroanthraquinones) prepared by nitrating anthraquinone with nitric acid in sulfuric acid and roughly purifying the product, 100 g of a 4% aqueous solution of sodium hydroxide (0.1 mole as sodium hydroxide) and 0.15 g of 5% palladium-carbon. The inside of the autoclave was purged with hydrogen, and the 1-nitroanthraquinone was hydrogenated with stirring at 30°C. In about 4 hours, the reaction stopped with the absorption of 0.083 mole of hydrogen. The hydrogen in the autoclave was replaced by nitrogen, and 0.00126 mole, calculated as oxygen, of air was caused to be absorbed by the reaction mixture at 30°C. over the course of 2 hours. The resulting precipitate was separated by filtration together with the catalyst. The filtrate was oxidized with air. The crystals precipitated were filtered, washed with water, and dried to afford 3.81 g of 1-aminoanthraquinone. As a result of a thin-layer chromatographic analysis, this product was found to be free from 1,5- and 1,8-diaminoanthraquinones and contain only traces of other diaminoanthraquinones. The purity of the product was more than 99% when determined by infrared absorption spectroscopy. The yield of the product was 95% on a purity basis.

Provenance & Evidence