反应详情

Under a nitrogen atmosphere, tetrahydrofuran (80 ml) was added to 4-bromophenyl isocyanate 30 (10.0 g), and a solution of cyclopropylamine 1 (3.17 g) in tetrahydrofuran (20 ml) was added dropwise with stirring under ice-cooling. After the completion of the dropwise addition, the mixture was stirred at room temperature for 3 hrs, and the reaction mixture was concentrated under reduced pressure. Diethyl ether-hexane [1:1 (volume ratio), 100 ml] was added to the residue and, after stirring, the crystals were collected by filtration and dried to give 1-(4-bromo-phenyl)-3-cyclopropyl-urea 31 (12.9 ġ, over weight) as colorless crystals, which were used for the next step without purification.

1. temperaturecooling
2. additionAfter the completion of the dropwise addition
3. stirringthe mixture was stirred at room temperature for 3 hrs
4. concentrationthe reaction mixture was concentrated under reduced pressure
5. additionDiethyl ether-hexane [1:1 (volume ratio), 100 ml] was added to the residue
6. stirringafter stirring
7. filtrationthe crystals were collected by filtration
8. customdried