反应详情

温度

7.5 °C

In a 2.5 L three-necked round-bottom flask 2-ethyl-6-methyl aniline (250 g, 1.85 mol) is dissolved in DCM (900 mL) and cooled to 5-10° C. Bromine (310.3 g, 1.94 mol) is added over a period of 105 min such as to keep the temperature at 5-15° C. An aq. 32% NaOH solution (275 mL) is added over a period of 10 min to the greenish-grey suspension while keeping the temperature of the reaction mixture below 25° C. DCM (70 mL) and water (100 mL) are added and the phases are separated. The aq. phase is extracted with DCM (250 mL). The combined org. phases are washed with water (300 mL) and concentrated at 50° C. to afford the 4-bromo-2-ethyl-6-methyl-aniline (389 g) as a brown oil; 1H NMR (CDCl3): δ 1.27 (t, J=7.3 Hz, 3H), 2.18 (s, 3H), 2.51 (q, J=7.3 Hz, 2H), 3.61 (s br, 1H), 7.09 (s, 2H).

1. customat 5-15° C
2. customthe temperature of the reaction mixture below 25° C
3. customthe phases are separated
4. extractionThe aq. phase is extracted with DCM (250 mL)
5. washphases are washed with water (300 mL)
6. concentrationconcentrated at 50° C.