反应详情

17.9 g (51.4 mMol) 6-Triisopropylsilanyloxy-benzofuran-3-carboxylic acid methyl ester are dissolved in 200 ml DMF. Then 34 g (108 mMol) tetrabutylammoniumfluorid trihydrate are added. After 30 min, the mixture is poured into 400 ml EtOAc and 600 ml water, the aq. phase is separated off and extracted 3 times with EtOAc. The organic layers are washed 4 times with water, brine and dried (Na2SO4). Then char coal is added and the mixture filtered. Partial concentration of the filtrate gives the crystalline title compound, which is filtered off and washed with ether and hexane: m.p.: 200-201° C. More product can be isolated from the filtrate by addition of 280 g SiO2, concentration, application to a chromatography column (SiO2; hexane/EtOAc 3: 1) and eluation with hexane/EtOAc 3:1.

1. customthe aq. phase is separated off
2. extractionextracted 3 times with EtOAc
3. washThe organic layers are washed 4 times with water, brine
4. dry with materialdried (Na2SO4)
5. additionThen char coal is added
6. filtrationthe mixture filtered