Process to produce tetrabromobisphenol with the reduced formation of alkyl bromide by-products
US5475153A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 4, 1995 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Jan 4, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/62
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of 4,4'-isopropylidene bis(2,6-dibromophenol), also known as tetrabrombisphenol A, that dramatically reduces the formation of alkyl bromide by-products. Bisphenol A is brominated with a C.sub.3 to C.sub.5 n-alcohol in a water mixture to suppress the formation of alkyl bromides. The bisphenol A is brominated between 15.degree. C. and 25.degree. C. and then heated at a 55.degree. C. to 70.degree. C. to insure bromination is complete. The tetrabrombisphenol A is then filtered from the reaction mixture and dried. Tetrabromobisphenol A produced from this process typically has a melting point of 180.degree. C. or higher, and is typically greater than 98% pure. Hydrogen peroxide is optionally combined with the reactants to reduce the amount of added bromine necessary for the bromination of the tetrabromobisphenol A.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.