반응 #7564

반응 방정식

boron tribromide

2,4-dimethoxytoluene

ethyl acetate

sodium hydroxide

→

2,4-dihydroxytoluene

수율 94.1%

용매

pentane

반응 조건

후처리

1. 1
   기타The starting material 2,4-dihydroxytoluene was prepared
2. 2
   workup.STIRRINGAfter stirring for 10 minutes
3. 3
   기타the organic layer was separated
4. 4
   추출the aqueous layer extracted with ethyl acetate
5. 5
   추출The combined organic extract
6. 6
   세척was washed with brine
7. 7
   건조dried (MgSO4)
8. 8
   기타the solvent removed by evaporation
9. 9
   기타The residue was purified by flash chromatography
10. 10
    세척eluting with methylene chloride/ethyl acetate (9/1)

실험 절차

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.

출처