Method for the production of 3,3'4,4'-tetraaminobiphenyl
US5041666A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1987 |
| Grant date | Aug 20, 1991 |
| Priority date | — |
| Expiry date | Aug 6, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C211/50
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method is provided for the production of 3,3', 4,4'-tetraaminobiphenyl (TAB) from biphenyl comprising the following steps: PA0 1) acetylating the biphenyl in the presence of an appropriate Friedel-Crafts catalyst to obtain 4,4'-diacetylbiphenyl (DAcB); PA0 2) oximating the DAcB to form DAcB dioxime; PA0 3) subjecting the dioxime to a double Beckmann rearrangement to obtain N,N-diacetylbenzidine (DiAcBz); PA0 4) nitrating the DiAcBz to obtain 3,3'-dinitro-N,N-diacetylbenzidine (DNAcBz) PA0 5) removing the acetyl groups of the DNAcBz by basic hydrolysis to form 3,3'-dinitrobenzidine (DNB); and PA0 6) reducing the nitrate groups of the DNB to form TAB.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.