反应 #1753628

反应方程式

HBr

5-Amino-2-methylphenol

HBr

NaNO2

→

title compound

收率 20.0%

5-Bromo-2-methylphenol

收率 20.0%

溶剂

H2O

H2O

反应条件

后处理

1. 1
   温度maintaining a temperature below 0° C
2. 2
   workup.STIRRINGThe mixture was stirred for 30 min below 0° C
3. 3
   workup.ADDITIONwas added dropwise
4. 4
   温度refluxed for 2 h
5. 5
   温度The reaction was cooled
6. 6
   过滤filtered through celite
7. 7
   workup.ADDITIONThe filtrate was diluted with water
8. 8
   萃取extracted with EtOAc
9. 9
   萃取The organic extract
10. 10
    干燥was dried over Na2SO4
11. 11
    浓缩concentrated under reduced pressure
12. 12
    其他The residue was purified by column chromatography (2.5% EtOAc-97.5% Hexane)

实验过程

5-Amino-2-methylphenol (5 g, 0.04 mol) was dissolved in HBr (20 mL) and H2O (20 mL) was added dropwise maintaining a temperature below 0° C. The resulting mixture was stirred for 5 min and a solution of NaNO2 (2.76 g, 0.04 mol) in H2O (7.5 mL) was added dropwise. The mixture was stirred for 30 min below 0° C. Then a solution of cuprous bromide (5.73 g, 0.04 mol) in HBr (7.5 mL) cooled to 0° C. was added dropwise. The resulting mixture was warmed to RT and then refluxed for 2 h. The reaction was cooled and filtered through celite. The filtrate was diluted with water and extracted with EtOAc. The organic extract was dried over Na2SO4, and concentrated under reduced pressure. The residue was purified by column chromatography (2.5% EtOAc-97.5% Hexane) to give the pure title compound (1.57 g, 20%). 1H NMR (500 MHz, CDCl3): δ 6.97 (s, 3H), 4.89 (s, 1H), 2.19 (s, 3H).

来源