反应详情

温度

80 °C

10 g (0.42 mol) of 3,6-dibromo-2-methylbenzaldehyde and 178.5 g (0.272 mol) of a 25% strength aqueous solution of hydroxylamine sulfate are mixed in 1.2 l of toluene and heated at 80° C. Over a period of 2 h, 109.2 g (1.36 mol) of 50% strength NaOH are then added dropwise such that the pH is between 3 and 5. Stirring at 80° C. is continued for 1 h, the mixture is stirred at room temperature overnight and the phases are then separated at 80° C. The organic phase is washed once with 350 ml of water. The organic phase is concentrated and the residue is recrystallized from cyclohexane. This gives 113.9 g (93% of theory) of the aldoxime.

1. waitis continued for 1 h
2. stirringthe mixture is stirred at room temperature overnight
3. customthe phases are then separated at 80° C
4. washThe organic phase is washed once with 350 ml of water
5. concentrationThe organic phase is concentrated
6. customthe residue is recrystallized from cyclohexane