2,6-Dimethylnitrobenzene → 2,4,6-Trimethylaniline

Participants

Reaction Steps

The 2,6-dimethylnitrobenzene is reduced to the amine, i.e., 2,6-dimethylaniline in the presence of a Raney nickel catalyst at a temperature of 25° C. and a pressure of 70 atmospheres: ##STR5## Mesidine (2,4,6-trimethylaniline) can be obtained in a similar manner by nitration of mesitylene followed by reduction. The aromatic amine is then reduced to an aliphatic amine with hydrogen in the presence of a hydrogenation catalyst such as Rh/Al2O3 in the range of 150 atmospheres and a temperature range of 90°-100° C., thusly: ##STR6## The thus formed 2,6-dimethylcyclohexylamine is then phosgenated to 2,6-dimethylcyclohexylisocyanate in the presence of chlorobenzene or dichlorobenzene solvent using excess phosgene and a two-stage temperature reaction wherein the first stage is carried out at -20° to 20° C. and the second from 110° to 180° C. while maintaining the reaction at a pressure in the range of 1 to 15 atmospheres: ##STR7##

Provenance & Evidence