Catalytic hydrogeneration of nitrobenzene to 4-aminodiphenylamine in the presence of a hydroxyl compound and a solvent
US5977411A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jun 10, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C209/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention provides a method for preparing 4-ADPA by charging nitrobenzene into a reaction zone under hydrogen pressure in the presence of a strong organic base and a catalyst for hydrogenation. The method provides the convenience and economy of a one-step process, while producing improved yields and selectivities. The invention further provides for various embodiments of the foregoing which are suitable for the production of 4-ADPA, and the hydrogenation or reductive alkylation to produce PPD. Important to the invention are the molar ratios of aniline to nitrobenzene and nitrobenzene to the strong organic base and the choice and use of hydrogenation catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.