Preparation of boron trichloride
US4210631A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1979 |
| Grant date | Jul 1, 1980 |
| Priority date | — |
| Expiry date | Mar 26, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B35/061
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Boron trichloride is prepared in substantially stoichiometric quantities by free-radical chlorination of borate ester, e.g., trimethyl borate, at temperatures of between about 20.degree. C. and 100.degree. C., more preferably between about 40.degree. C. and about 90.degree. C. The mole ratio of chlorine to borate ester is from about 5.5:1 to about 7.5:1. Reactor pressures are moderate, e.g., generally less than 3 atmospheres absolute. Atmospheric pressure can be used. An inert liquid organic solvent, e.g., carbon tetrachloride, can be used as the reaction medium. Gaseous reaction products are removed from the reactor during the chlorination reaction. In addition to boron trichloride, carbon monoxide (rather than phosgene) and hydrogen chloride are the principal products of the chlorination reaction. Phosgene is produced in substantially lower amounts than when chlorination is conducted at autogeneous pressures and the chlorine:trimethyl borate mole ratio is 9:1 or more. The boron trichloride product is separated from the carbon monoxide, hydrogen chloride and phosgene products, and recovered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.