Method of preparing mixtures of bromophenols and benzoquinones
US6693221B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2003 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Apr 4, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/62
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method is described for the simultaneous preparation of 4-bromophenols and p-benzoquinones, intermediates useful in the preparation of hydroquinones and 4,4′-dihydroxybiphenyls respectively. Hydroquinones and 4,4′-dihydroxybiphenyls are useful monomers for the preparation of a variety of polymers. In one example phenol is reacted with in the presence of HBr, a catalytic amount of cupric bromide and a stoichiometric excess of oxygen under relatively mild conditions to provide a mixture of the phenol, 4-bromophenol, and 1,4-benzoquinone. Phenol conversion was 54 percent and selectivities for bromophenol and benzoquinone were 23% and 37% respectively. Limiting the amount of HBr present in the reaction mixture was shown to control the amount of benzoquinone produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.