反应 #1885099

反应方程式

K2CO3

4,6-dibromo-2-fluoro-3-methylphenol

MeI

→

1,5-dibromo-3-fluoro-2-methoxy-4-methylbenzene

溶剂

CH3CN

反应条件

后处理

1. 1
   workup.ADDITIONby adding, at room temperature
2. 2
   温度The reaction mixture was cooled to room temperature
3. 3
   过滤solid was filtered off by filtration
4. 4
   洗涤washing with CH2Cl2 (˜100 mL×2)
5. 5
   其他Filtrate was collected
6. 6
   其他solvent was removed in in vacuo
7. 7
   其他to remove some darker color baseline impurities and solid
8. 8
   workup.DISSOLUTIONinitially dissolved in CH3CN),
9. 9
   洗涤washing with CH2Cl2 (˜100 mL×3)
10. 10
    其他Filtrate was collected
11. 11
    其他solvent was removed in vacuo

实验过程

1,5-dibromo-3-fluoro-2-methoxy-4-methylbenzene was prepared from a homogeneous CH3CN (1 L) solution of 4,6-dibromo-2-fluoro-3-methylphenol (˜225.1 g, 792.8 mmol) by adding, at room temperature, K2CO3 (131.5 g, 1.18 mol), followed by MeI (74 mL, 951 mmol). The cloudy solution was stirred at 30° C. and, as monitored by LC, the reaction went to completion at 21 h. The reaction mixture was cooled to room temperature, solid was filtered off by filtration, washing with CH2Cl2 (˜100 mL×2). Filtrate was collected, solvent was removed in in vacuo. Crude product was suspended in CH2Cl2 (200 mL) and the solution was passed through a silica gel pad (˜50 g of silica gel) (note, to remove some darker color baseline impurities and solid initially dissolved in CH3CN), washing with CH2Cl2 (˜100 mL×3). Filtrate was collected, solvent was removed in vacuo. 1,5-dibromo-3-fluoro-2-methoxy-4-methylbenzene was obtained as an off-white solid: 249.46 g (>99% yield); 1H NMR (300 MHz, CDCl3) δ 7.53 (d, J=2.1, 1H), 3.92 (s, 3H), 2.29 (d, J=2.8, 3H).

来源