Process for the preparation of bromoanthraquinones
AssigneeCiba-Geigy Corporation
InventorsTibor Somlo, Johann Regli
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Abstract
A process for the preparation of pure bromoanthraquinones by denitrobrominating corresponding nitroanthraquinones is described. The process comprises treating nitroanthraquinones of the formula I ##STR1## wherein X is hydroxy, mercapto, carboxy or halogen and m is 1, 2, 3 or 4 and n is 1 or 2, in the temperature range from 200.degree. to 350.degree. C. Bromoanthraquinones of more than 95% purity are valuable starting materials for dye synthesis and can be used directly without further purification.
Claims8
A process for the preparation of pure bromoanthraquinones by denitrobrominating corresponding nitroanthraquinones, which process comprises treating nitroanthraquinones of the formula I ##STR3## wherein X is hydroxy, mercapto, carboxy or halogen, m is 1, 2, 3 or 4 and n is 1 or 2, with elementary bromine in the temperature range from 200.degree. C. to 350.degree. C.
Dependencies are inferred from the claim text.