Process for preparing isocyanates
US5189205A · kind A · utility
12Cited by
5References
28Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1992 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Mar 16, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing isocyanates comprising (a) contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and an organic, nitrogenous base to produce the corresponding ammonium carbamate salt, and (b) reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent to produce the corresponding isocyanate. A second embodiment comprises recovering the ammonium carbamate salt of step (a) prior to reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent in the presence of an aprotic organic solvent and an organic, nitrogenous base.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.