Method for the preparation of chloroformate compositions
US4638077A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1985 |
| Grant date | Jan 20, 1987 |
| Priority date | — |
| Expiry date | Oct 24, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C68/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Chloroformate compositions, particularly bischloroformate compositions, are prepared by the reaction of phosgene with a hydroxy compound, preferably a dihydroxy compound such as bisphenol A, in a heterogeneous mixture, while adding a hydrogen chloride scavenger comprising aqueous base as necessary and maintaining a pH of 0.5-8 during the phosgene addition. When a polyhydroxy compound is employed and the temperature is above 30.degree. C., the phosgene addition rate is maintained at a level high enough to effect rapid and complete reaction with dissolved hydroxy compound. This method uses substantially less phosgene than methods involving a higher pH.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.