反应详情

4-t-Butyl-pyridine N-oxide (11.0 g, 72.9 mmole) is dissolved in 200 ml dichloromethane in a 500 ml one neck round bottom flask under nitrogen. The solution is treated with trimethyloxonium tetrafluoroborate (10.8 g, 72.9 mmole), is stirred 1h at room temperature, and the volatiles are removed in vacuo. The solid residue is dissolved in 200 ml methanol in a 500 ml one neck round bottom flask. The solution is heated to reflux, is treated with ammonium persulfate (3.3 g, 14.5 mmole) in 15 ml water, and the reaction mixture is vigorously refluxed for 30 min. The reaction is treated with a second lot of ammonium persulfate (1.65 g, 7.2 mmole) in 7 ml water and is refluxed for an additional 1 h. The reaction is cooled and the bulk of the methanol is removed in vacuo. The residue is diluted with 300 ml conc ammonium hydroxide and the mixture is extracted with 4×100 ml dichloromethane. The combined organics are dried over potassium carbonate and are concentrated in vacuo to a yellow oil. The crude material is chromatographed over 400 g silica gel (230-400 mesh), eluting with 40% acetone/hexane, while collecting 50 ml fractions. Fractions 26-52 are combined and concentrated to afford 8.79 g (73%) of 4-t-Butyl-2-hydroxymethyl-pyridine as a yellow oil.

1. customthe volatiles are removed in vacuo
2. dissolutionThe solid residue is dissolved in 200 ml methanol in a 500 ml one neck round bottom flask
3. temperatureThe solution is heated
4. temperatureto reflux
5. temperaturethe reaction mixture is vigorously refluxed for 30 min
6. temperatureis refluxed for an additional 1 h
7. temperatureThe reaction is cooled
8. customthe bulk of the methanol is removed in vacuo
9. additionThe residue is diluted with 300 ml conc ammonium hydroxide
10. extractionthe mixture is extracted with 4×100 ml dichloromethane
11. dry with materialThe combined organics are dried over potassium carbonate
12. concentrationare concentrated in vacuo to a yellow oil
13. customThe crude material is chromatographed over 400 g silica gel (230-400 mesh)
14. washeluting with 40% acetone/hexane
15. customwhile collecting 50 ml fractions
16. concentrationconcentrated