Process for producing diphenylamines or N,N'-diphenylphenylenediamines
US4871875A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1988 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Sep 14, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C209/18
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Diphenylamines or N,N'-diphenyl-phenylenediamines can be obtained by heat-reacting an aniline or a phenylenediamine with preferably an excess of a phenol in an amount of 4 to 20 moles per mole of the aniline or phenylenediamine in the presence of a hydrogen transfer catalyst and a cyclohexanone corresponding to said phenol. The excess phenol used in the reaction undergoes reduction in the reaction system to form a cyclohexanone, which in turn reacts with the aniline or phenylenediamine to form a Schiff base and is thus consumed. The Schiff base forms the intended product by means of a dehydrogenation reaction, and the hydrogen evolved at this time reduces the phenol to form a cyclohexanone. The phenol present in excess thus becomes in the system a solvent, a starting material for the cyclohexanone, and an acceptor of the hydrogen that forms as a by-product at the time of formation of the intended product. Hence, it becomes possible to obtain the intended product at a high selectivity from the anilines and phenylenediamines. The process of this invention is an advantageous process for the industrial production of especially the nuclearly substituted diphenylamines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.