Process for the preparation of N,O-disubstituted urethanes useful for the preparation of isocyanates

摘要

A process for the preparation of N,O-disubstituted urethanes. Urea or polyurets, primary amines and alcohols are reacted at 120 DEG -350 DEG C. in the presence of N-substituted urethanes and/or N-mono- or N,N'-disubstituted ureas or polyureas. In a preferred embodiment, the reactants further include catalysts known to be useful in esterification of carboxylic acids. The urethanes produced in accordance with this process are particularly useful as starting materials for preparation of isocyanates.