| 摘要 |
PROBLEM TO BE SOLVED: To efficiently obtain the subject compound at high reaction rate using a simple apparatus even in the case of using a low-boiling alcohol, by reaction between urea or a derivative therefrom and an alcohol in the presence of a high-boiling solvent and a catalyst. SOLUTION: This compound, a dialkyl carbonate, is obtained by reaction between urea or an urea derivative of the formula R1 R2 N-CO-NR3 R4 (R1 to R4 are each H or a 1-4C alkyl) such as methylurea or ethylurea and an alcohol (normally, a 1-10C aliphatic alcohol, esp. pref. 3-6C alcohol) in the presence of a high-boiling solvent >=180 deg.C, pref. >=195 deg.C, more pref. >=220 deg.C (pref. a hydrocarbon such as tetradecane or tetramethylpentadecane, ether such as diphenyl ether) and a catalyst (e.g. zinc oxide, magnesium oxide, lead acetate, copper acetate, dibutyltin oxide, tetrabutoxytitanium) pref. under the atmospheric pressure at 100-250 deg.C or so for 2-10h or so. |
