Process for production of 1-aminoanthraquinone
US4840749A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1987 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Jun 16, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B1/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for producing 1-aminoanthraquinone, which comprises PA1 (a) a step of oxidizing 1-nitronaphthalene in the liquid phase with an acidic aqueous solution containing a ceric ion as an oxidizing agent and separating crystals containing 5-nitro-1,4-naphthoquinone and the acidic aqueous solution containing a cerium ion from the resulting reaction mixture, PA1 (b) a step of subjecting the 5-nitro-1,4-naphthoquinone obtained in step (a) to Diels-Alder reaction with 1,3-butadiene in a solvent, precipitating crystals containing the resulting 5-nitro-1,4,4a,9a-tetrahydroanthraquinone, separating them by filtration, separating and recovering the unreacted 1-nitronaphthalene and the solvent in the filtrate in a separation tower, and recycling 1-nitronaphthalene to step (a) for use as the starting material and re-using the recovered solvent for the Diels-Alder reaction, PA1 (c) a step of reducing 5-nitro-1,4,4a,9a-tetrahydroanthraquinone obtained in step (b), separating crystals containing 1-aminoanthraquinone and purifying them, and PA1 (d) a step of electrolytically oxidizing the acidic aqueous solution containing a cerium ion separated in step (a) to convert the cerous ion in the aci…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.