反応 #1121794

反応方程式

1-(4-bromo-pyridin-2-yl)-4,4-dimethoxy-butan-1-one

1-(4-Bromo-pyridin-2-yl)-4,4-dimethoxy-butan-1-one

trifluoroacetic acid

→

4-(4-bromo-pyridin-2-yl)-4-oxo-butyraldehyde

4-(4-Bromo-pyridin-2-yl)-4-oxo-butyraldehyde

溶媒

CH2Cl2

反応条件

後処理

1. 1
   濃縮The reaction is concentrated
2. 2
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (150 mL)
3. 3
   洗浄washed with water 3 times
4. 4
   乾燥dried over Na2SO4
5. 5
   その他the solvent evaporated
6. 6
   その他The residue is purified by flash column chromatography (30% EtOAc in hexanes)

実験手順

To a solution of 1-(4-bromo-pyridin-2-yl)-4,4-dimethoxy-butan-1-one (2) (crude from Step 2, 11 g, 38.2 mmol) in 100 of CH2Cl2 at room temperature is added trifluoroacetic acid (10.9 g, 95.4 mmol) and the reaction mixture is stirred overnight. The reaction is concentrated, the residue dissolved in ethyl acetate (150 mL) and washed with water 3 times. The organic layers are combined, dried over Na2SO4 and the solvent evaporated. The residue is purified by flash column chromatography (30% EtOAc in hexanes) to give 4-(4-bromo-pyridin-2-yl)-4-oxo-butyraldehyde (3) as an yellow oil. (4.16 g, 45%): MS ES+244.04.

出典