Reacción #1121794

Ecuación de reacción

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

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónThe reaction is concentrated
2. 2
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (150 mL)
3. 3
   Lavadowashed with water 3 times
4. 4
   Secadodried over Na2SO4
5. 5
   Otrothe solvent evaporated
6. 6
   OtroThe residue is purified by flash column chromatography (30% EtOAc in hexanes)

Procedimiento

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.

Fuente