Process for producing cyclic ureas.

摘要

A process for producing a cyclic urea by reacting a diamine directly with phosgene with a high yield and a cheap cost is provided, which process comprises reacting a diamine expressed by the formula R-HN-R min -NH-R wherein R represents hydrogen atom or a lower alkyl group and R min represents dimethylene group, trimethylene group, tetramethylene group or a lower alkyl group-substituted dimethylene group, trimethylene group or tetramethylene group except for three particular combination of R with R min , with phosgene substantilly in the presence of water and a dehydrochlorinating agent to obtain a cyclic urea expressed by the formula <CHEM> wherein R and R min are as defined above. n