Реакция #1121794

Уравнение реакции

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

Растворители

CH2Cl2

Условия реакции

Обработка

1. 1
   КонцентрированиеThe reaction is concentrated
2. 2
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (150 mL)
3. 3
   Промывкаwashed with water 3 times
4. 4
   Сушкаdried over Na2SO4
5. 5
   Другоеthe solvent evaporated
6. 6
   ДругоеThe residue is purified by flash column chromatography (30% EtOAc in hexanes)

Методика

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.

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