Reacción #7564

Ecuación de reacción

boron tribromide

2,4-dimethoxytoluene

ethyl acetate

sodium hydroxide

→

2,4-dihydroxytoluene

Rendimiento 94.1%

Disolventes

pentane

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe starting material 2,4-dihydroxytoluene was prepared
2. 2
   workup.STIRRINGAfter stirring for 10 minutes
3. 3
   Otrothe organic layer was separated
4. 4
   Extracciónthe aqueous layer extracted with ethyl acetate
5. 5
   ExtracciónThe combined organic extract
6. 6
   Lavadowas washed with brine
7. 7
   Secadodried (MgSO4)
8. 8
   Otrothe solvent removed by evaporation
9. 9
   OtroThe residue was purified by flash chromatography
10. 10
    Lavadoeluting with methylene chloride/ethyl acetate (9/1)

Procedimiento

The starting material 2,4-dihydroxytoluene was prepared by adding boron tribromide (3.1 ml, 3.2 mmol) to a solution of 2,4-dimethoxytoluene (1 g, 6.5 mmol) in pentane (10 ml) at −70° C. The reaction mixture was allowed to warm to ambient temperature and the mixture stirred for a further 2 hours. Ice water and ethyl acetate were then added and the aqueous layer basified to pH9.5 with 2M aqueous sodium hydroxide solution. After stirring for 10 minutes, the organic layer was separated and the aqueous layer extracted with ethyl acetate. The combined organic extract was washed with brine, dried (MgSO4) and the solvent removed by evaporation. The residue was purified by flash chromatography eluting with methylene chloride/ethyl acetate (9/1) to give 2,4-dihydroxytoluene (759 mg, 94%) as a white solid.

Fuente