反应详情

4-Acetylamino-3-pyridinol N,N-diethylcarbamate (3.43 g) was dissolved in tetrahydrofuran (75 mL) and then the reaction mixture was chilled in an ice-water bath. Borane/methyl sulfide (BMS) was added (3.25 mL, 2.60 g) and the reaction mixture was stirred in the cold bath for 30 minutes. At the end of this time an additional 3.0 mL of BMS was added and stirring was continued for 3 hours. The reaction mixture was then poured into ice/conc. HCl, stirred for 30 minutes, basified with NH3 /water and then extracted with ethyl acetate. The organic phase was then dried, concentrated and purified by flash chromatography to give 0.86 g of chromatographically pure product. This product was combined with a crop obtained from another run and recrystallized from hexane to give an analytically pure material, m.p. 107°-108° C.

1. temperaturethe reaction mixture was chilled in an ice-water bath
2. additionAt the end of this time an additional 3.0 mL of BMS was added
3. stirringstirring
4. waitwas continued for 3 hours
5. additionThe reaction mixture was then poured into ice/conc
6. extractionextracted with ethyl acetate
7. customThe organic phase was then dried
8. concentrationconcentrated
9. custompurified by flash chromatography
10. customto give 0.86 g of chromatographically pure product
11. customobtained from another run
12. customrecrystallized from hexane
13. customto give an analytically pure material, m.p. 107°-108° C.