Reaction #1161568

ord-9eac7e476097490e89ac406077e4a5dc

Reaction equation

CNC(=O)NC
1,3-dimethylurea
CNC(=O)NC.Cl
1,3-dimethylurea hydrochloride
NC(=O)Cl
carbamoyl chloride
CNC(=O)NC.Cl
1,3-dimethylurea hydrochloride
CN=C=O
methyl isocyanate

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    workup.ADDITIONis added by line 2 to reactor 3 which
  2. 2
    Otheris operated at 30° to 40° C

Procedure

A solution of carbamoyl chloride in a suitable solvent such as chlorobenzene is introduced by line 1 into reactor 3 and a slight excess of 1,3-dimethylurea in chlorobenzene usually containing some 1,3-dimethylurea hydrochloride in chlorobenzene is added by line 2 to reactor 3 which is operated at 30° to 40° C. A slurry of 1,3-dimethylurea hydrochloride (solid phase) and methyl isocyanate in chlorobenzene (liquid phase) is formed and the slurry is removed by line 4 to filter 5. The liquid phase from the filter is removed by line 6 to distillation column 7 wherein the solution is distilled to remove methyl isocyanate by line 8 after condensation in condensor 9. The chlorobenzene solvent from distillation column 7 is passed by line 10 to wash the filter and obtain a slurry of chlorobenzene and 1,3-dimethylurea hydrochloride.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US04391758uspto-grants-1983_07