| abstract |
The present invention relates to a process for the purification of diurethanes. This process comprises distilling one or more diurethanes corresponding to the general formula: R1 - (NHCOOR2)2 wherein R1: represents a substituted or an unsubstituted aromatic, araliphatic, cycloaliphatic or aliphatic hydrocarbon radical containing from 4 to 10 carbon atoms, wherein suitable substituents comprise alkyl groups containing from 1 to 4 carbon atoms, and R2: represents an alkyl radical containing from 1 to 6 carbon atoms, or a cycloaliphatic hydrocarbon radical containing 5 or 6 carbon atoms; in the presence of low-boiling alcohols at elevated temperatures. |