反応 #1248046

反応方程式

2-bromo-5-methoxy-benzaldehyde

BBr3

→

2-bromo-5-hydroxy-benzaldehyde

収率 38.5%

反応条件

後処理

1. 1
   その他the reaction is quenched with water
2. 2
   抽出extracted with ethyl acetate
3. 3
   洗浄The combined organic layers are washed with water, brine
4. 4
   乾燥dried over MgSO4
5. 5
   濃縮concentrated
6. 6
   その他purified by column chromatography

実験手順

To the solution of 2-bromo-5-methoxy-benzaldehyde (10 g, 46.5 mmol) at −78° C. is added BBr3 (25 g, 93.75 mmol) and allowed to warm to room temperature. After 2 h, the reaction is quenched with water and extracted with ethyl acetate. The combined organic layers are washed with water, brine, dried over MgSO4, concentrated and purified by column chromatography to afford 3.6 g of 2-bromo-5-hydroxy-benzaldehyde. To the solution of 2-bromo-5-hydroxy-benzaldehyde (1.45 g, 7.2 mmol in benzene (30 ml) and THF (6 ml) is added 1,3-propanediol (2.74 g, 36 mmol) and TsOH (37 mg, 0.22 mmol). The mixture is refluxed for 24. After cooling down, the solvent is evaporated. The residue is loaded on silica and purified by column chromatography to afford the titled compound (2.3 g) as brown oil.

出典