Process for preparing 4-aminodiphenylamines
US6140538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1999 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | Feb 3, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C209/38
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing an optionally substituted 4-aminodiphenylamine comprising reacting an optionally substituted aniline and an optionally substituted nitrobenzene in the presence of water and a base while controlling the water content so as to ensure a molar ratio of water to the base charged of not less than about 4:1 at the start of the coupling reaction and not less than about 0.6:1 at the end of the coupling reaction to produce 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or salts thereof. The coupling reaction is followed by a hydrogenation reaction where the coupling reaction product is hydrogenated in the presence of a hydrogenation catalyst and added water so as to ensure a molar ratio of total water to base of at least about 4:1 at the end of hydrogenation. Aqueous and organic phases are obtained and the optionally substituted 4-aminodiphenylamine recovered from the organic phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.