反応 #470556

反応方程式

4-Bromo-2-methylphenyl methyl carbonate

H2SO4

KNO3

→

4-bromo-2-methyl-5-nitrophenyl methyl carbonate

収率 71.8%

反応条件

後処理

1. 1
   workup.ADDITIONwas added portion-wise
2. 2
   温度maintaining the internal temperature below 5° C
3. 3
   workup.ADDITIONpoured over ice
4. 4
   抽出The aqueous layer was extracted with dichloromethane
5. 5
   洗浄washed with saturated NaHCO3 and water
6. 6
   乾燥dried over Na2SO4
7. 7
   濃縮concentrated
8. 8
   その他Purification by silica gel chromatography (0-5% ethyl acetate/hexanes)

実験手順

4-Bromo-2-methylphenyl methyl carbonate (4.0 g, 16.32 mmol) was added portion-wise to H2SO4 (12.0 mL) to generate a homogeneous solution. This solution was then cooled to 0° C. internal temperature and KNO3 (2.0 g, 19.6 mmol) was added portion-wise maintaining the internal temperature below 5° C. The reaction was stirred for 2 h and then poured over ice. The aqueous layer was extracted with dichloromethane, washed with saturated NaHCO3 and water, dried over Na2SO4, and concentrated. Purification by silica gel chromatography (0-5% ethyl acetate/hexanes) provided 4-bromo-2-methyl-5-nitrophenyl methyl carbonate (3.4 g, 71% yield). 1H NMR (400.0 MHz, DMSO-d6) δ 8.11 (s, 1H), 7.95 (s, 1H), 3.88 (s, 3H), 2.25 (s, 3H).

出典