反应详情

Under a nitrogen atmosphere, to N,N-carbonyldiimidazole (61.4 g) were added N,N-dimethylformamide (300 ml) and triethylamine (52.8 ml) and a solution of 2-fluoro-4-iodoaniline 47 (74.8 g) in N,N-dimethylformamide (75 ml) was added dropwise with stirring under ice-cooling. After the completion of the dropwise addition, the mixture was stirred at room temperature for 5 hrs. The reaction mixture was ice-cooled, and a solution (60 ml) of 40% methylamine in methanol was added dropwise. The mixture was stirred at room temperature for 1 hr, and the reaction mixture was added dropwise to water-toluene [2:1 (volume ratio), 1125 ml] under stirring. The precipitated crystals were collected by filtration and dried to give 1-(2-fluoro-4-iodophenyl)-3-methylurea 63 (87.9 g, yield 94.8%) as colorless crystals.

1. temperaturecooling
2. additionAfter the completion of the dropwise addition
3. stirringthe mixture was stirred at room temperature for 5 hrs
4. temperaturecooled
5. stirringThe mixture was stirred at room temperature for 1 hr
6. stirringunder stirring
7. filtrationThe precipitated crystals were collected by filtration
8. customdried