Process for preparing pure 1-nitroanthraquinone
US4031116A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1976 |
| Grant date | Jun 21, 1977 |
| Priority date | — |
| Expiry date | Jul 20, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C201/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Pure 1-nitroanthraquinone substantially free of dinitroanthraquinone is prepared by: PA1 1. Nitrating anthraquinone or a mixture which contains anthraquinone with at least 90% nitric acid at a temperature of at least 0.degree. C wherein the mole ratio of nitric acid to anthraquinone is less than 20 to 1; PA1 2. Stopping the reaction when the anthraquinone conversion is at least 50% by cooling the reaction mixture to a temperature of at most 20.degree. C and/or by adjusting the mole fraction of nitric acid in the reaction mixture to a value of at most 0.86; PA1 3. Precipitating 1-nitroanthraquinone by adjusting the mole fraction of nitric acid to a value of from 0.7 to 0.4 and/or by reducing the temperature to at most 20.degree. C; and PA1 4. Separating the precipitated 1-nitroanthraquinone and subjecting it to vacuum distillation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.