One-pot catalytic process for the synthesis of isocyanates

摘要

One-pot process for the synthesis of isocyanates, polyisocyanates or mixtures thereof which comprises the steps of:
i. preparing a mixture comprising an amine, an alcohol, an oxygen containing gas, carbon monoxide, a metal complex catalyst selected from the group consisting of macrocyclic complex catalysts and cobalt Shiff base catalysts; and a solvent selected from the group consisting of aliphatic or aromatic halocarbons, perhalogenated alcohols, halogenated ethers, halogenated ketones, perfluorinated hydrocarbons, polymers of chlorotrifluoroethylene having the formula -(CF 2 -CFCl) n wherein n is between 2 and 10, and mixtures thereof;
ii. subjecting the resulting mixture to a first heating under pressure;
iii. cooling and depressurizing the mixture resulting from the previous step; and
iv. subjecting the mixture of the previous step to a second heating to separate out the isocyanate product from the mixture.