PURPOSE: To prepare a slurry of anthraquinone fine crystals in sulfuric acid, by dissolving anthraquinone in concentrated sulfuric acid with heating, and adjusting the concentration of sulfuric acid first by adding sulfuric acid of specific concentration, and if necessary adding dilute sulfuric acid or water to the solution.
CONSTITUTION: Anthraquinone is dissolved completely in concentrated sulfuric acid (≥95%) by heating at 60W150°C. The objective slurry of anthraquinone fine crystals in sulfuric acid can be obtained by adding first a sulfuric acid of 50W80% concentration to the solution at 50W120°C to reduce the concentration of the sulfuric acid, and if necessary, adding a dilute sulfuric acid or water to the mixture at 50W 120°C to adjust the concentration of the sulfuric acid to 95W70%. The anthraquinone may have a substituent group such as halogen, OH, alkyl, allyloxy, acylamino, etc.
EFFECT: The use of the above fine crystalline slurry enables the smooth nitrification of anthraquinone.
YOSHIURA KOUICHI
FUJII SHIROU
