Co-production of an aromatic monoamine and an aromatic diamine directly from benzene or a benzene derivative through controlled nitration
US4740621A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1985 |
| Grant date | Apr 26, 1988 |
| Priority date | — |
| Expiry date | Nov 1, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C201/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A two-stage process for the co-production of aniline and m-phenylenediamine where, in the first stage, benzene, nitric acid, and sulfuric acid are reacted in a liquid phase to produce in greater amounts nitrobenzene (approximately 70%) and m-dinitrobenzene (approximately 30%), and in lesser or trace amounts o-dinitrobenzene and p-dinitrobenzene, and water; and in the second stage the products of the first stage are reacted with hydrogen in the gas phase to produce aniline (approximately 70%) and m-phenylenediamine (approximately 30%) in greater amounts, and o-phenylenediamine and p-phenylenediamine in lesser amounts, and water. The reaction products are separated by distillation. The first stage of a preferred embodiment of the process is characterized in that a concentrated mixture of nitric acid and sulfuric acid are fed along with mononitrobenzene to a first reactor for producing dinitrobenzene, and then the dilute acid mixture recovered from this first reactor is fed along with benzene to a second reactor for producing the mononitrobenzene used as a reactant in the first reactor. The second stage, which provides the aniline and m-phenylenediamine in major amounts, is characteri…
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