Solventless preparation of ester-substituted diaryl carbonates
US6469192B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2001 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Jul 24, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C68/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
High yields of ester-substituted diary carbonates such as bis-methyl salicyl carbonate were obtained by the condensation of ester-substituted phenols with phosgene in the presence of a phase transfer catalyst (PTC) and optionally a tertiary amine catalyst in a solvent free reaction system comprising an aqueous phase held at a pH of 8.3 or higher. The optimized conditions of the present invention use an excess of ester-substituted phenol relative to phosgene and high conversion of phosgene to ester-substituted diaryl carbonate is observed. The product ester-substituted diaryl carbonate may be conveniently isolated as a solid by filtration or as a liquid in which the excess ester-substituted phenols serves as solvent. The method represents an attractive route for the manufacture of bis methyl salicyl carbonate and ester-substituted diaryl carbonates generally.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.