Preparation of Anthraquinone and Alizarine.

Practical Magazine 19, 1876

(Chemistry applied to the Arts, Manufactures, &c.
Dyeing, Calico Printing, Bleaching, Tanning, and Allied Subjects.)

The process adopted for this purpose by Messrs. BAYER, WESTKOTT, and PILLER is as follows: — A mixture of one part of anthracene with about four or five of manganese is subjected to distillation. The anthraquinone, formed in this operation and on the employment of heat, is dissolved in Nordhausen sulphuric acid. The solution is neutralized with chalk, then the precipitate is washed and exhausted repeatedly by boiling water, and the solution of anthraquinone and sulphate of lime is mixed with soda. The salt of soda which is formed and remains in solution is separated from the carbonate of lime by rest and decanting, and the solution of sodic salt is evaporated to dryness after the addition of caustic soda. The residuum is then melted until a specimen washed and dissolved in water appears blue violet. This point having been reached, the mass is dissolved in water, and the alizarine of the solution is separated by means of any acid.

- Bericht der deutschen Chemischer Gesellschaft, 1876, p. 206.

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