Preparation of pure 1,5-dinitroanthraquinone
US3996251A · kind A · utility
1Cited by
1References
10Claims
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Assignee
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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 35% is 1,5-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 1,5-dinitroanthraquinone. Preferred solvents are 1-chloronaphthalene, sulpholane and adipic acid dinitrile. The temperature of dissolution ranges from about 120.degree. C up to the boiling point and cooling is by about 10.degree. to 200.degree. C to a temperature not below about 0.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.