Process for the production of N-methylcarbamates
US4659845A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 1985 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | May 7, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Process for the production of N-methylcarbamates: ##STR1## (wherein RO- is the radical of a substituted phenol or of a naphthol), wherein: PA0 in a first reaction step methylamine and diphenyl carbonate are reacted with each other, operating in the liquid phase and as a continuous process, in order to form phenol and phenyl-N-methylurethane; PA0 in a second reaction step phenyl-N-methylurethane, within the related reaction mixture outcoming from the first step, is thermally continuously decomposed, to yield a gaseous stream containing methyl isocyanate, from which the components different than methyl isocyanate are condensed off; PA0 in a third step the methyl isocyanate stream, outcoming from the second step, after an optional preliminary condensation, is continuously fed and contacted with a solution of a substituted phenol or of a naphthol in an inert organic solvent, containing a basic catalyst, to form N-methylcarbamate (I); PA0 N-methylcarbamate (I) is finally recovered from the reaction mixture outcoming from the third step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.