摘要 |
A method for separating non-vicinal from vicinal toluene diamines comprises contacting a solution of the diamines with a 10-100% saturated solution of a compound of a metal of atomic number 22-30, 40-48 or 72-80, the respective solvents being substantially immiscible and separating the non-vicinal diamine solution from the metal compound-vicinal diamine solution or precipitate. The non-vicinal diamine may be converted to diisocyanate by reaction with phosgene; the vicinal diamine may be recovered from the complex. |