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
wherein R represents hydrogen atom or a lower alkyl group and R' 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', with phosgene substantilly in the presence of water and a dehydrochlorinating agent to obtain a cyclic urea expressed by the formula
wherein R and R' are as defined above.
本发明提供了一种通过二胺直接与
光气反应生产环状
脲的工艺,其产率高且成本低,该工艺包括将式中 R 代表氢原子或低级烷基,R'代表二
甲苯基团、
三甲苯基团、四
甲苯基团或低级烷基取代的二
甲苯基团、
三甲苯基团或四
甲苯基团(R 与 R'的三种特定组合除外)的二胺与
光气在
水和脱氢
氯化剂存在下进行反应,得到式中 R 和 R'如上定义的环状
脲。