Preparation of pure 1,8-dinitroanthraquinone
US3996252A · kind A · utility
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11Claims
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Key dates
| Filing date | Apr 1, 1976 |
| Grant date | Dec 7, 1976 |
| Priority date | — |
| Expiry date | Apr 1, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C225/34
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A mixture of dinitroanthraquinones of which at least 70% is 1,8-dinitroanthraquinone is dissolved at elevated temperature in a halogenated aromatic hydrocarbon, a carboxylic acid nitrile or a cyclic sulphone and is thereafter cooled selectively to precipitate substantially pure 1,8-dinitroanthraquinone. Preferred solvents are 1-chloronaphthalene, sulpholane and adipic acid dinitrile. The particular temperature of dissolution and cooling will depend upon the particular solvent.
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