| 摘要 |
PURPOSE:To obtain 1,3-dimethyl-2-imidazolidinone, an improved solvent for high polymer compounds, in high yield, by reacting N,N-dimethylethylenediamine with urea in the presence of a polar solvent at a reaction temperature of two stages. CONSTITUTION:In producing 1,3-dimethyl-2-imidazolidinone from N,N'- dimethylethylenediamine and urea(feed molar ratio of urea to N,N'- dimethylethylenediamine is preferably 0.6-1.2), firstly the reaction is carried out in a polar solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea, etc. at <=140 deg.C, preferably 100-130 deg.C until formation of 1,1'- dimethyl-1,1'-dimethylenebisurea is finished and the reaction is successively done at >=180 deg.C, preferably 200-260 deg.C to give 1,3-dimethyl-2-imidazolidinone(DMI). Separation of the solvent is not required and the process is simple when DMI is especially used as the solvent.
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