1-Amino-2-methylanthraquinone → 1-Amino-4-bromo-2-methylanthraquinone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1-Amino-2-methylanthraquinone (300 g) is slurried with 1500 ml of HOAc in a 5-liter flask. The temperature is raised to 40° C. Neat bromine (405 g) is added over 21/2 hours with stirring at 40°-50° C. The mixture is stirred for 20 additional minutes and filtered. The solids to recovered are washed with HOAc and water and sucked dry with an aspirator and transferred to a reaction flask along with 150 g of NaHSO3 and 1.5 liters of water. The mixture is gradually heated to 90° C. (over two hours) with stirring to give 1-amino-2-methyl-4-bromoanthraquinone (A) (also marketed as AMBAX) as a solid which is recovered from the reaction mixture by filtration in 90% yield, rinsed with water and dried overnight at 155° C. and 1 mm Hg absolute vacuum.

Herkunft & Nachweise