反应详情

To a solution of Intermediate (S)-methyl 1-hydroxypropan-2-ylcarbamate (2.65 g, 20 mmol) and triethylamine (7.0 ml, 50 mmol) in anhydrous dichloromethane (100 mL) was added methanesulfonyl chloride (1.91 mL, 23.9 mmol). The mixture was stirred at rt for 3 h and was then extracted with ethyl acetate. The organic layer was washed with 1N sodium hydroxide solution and brine, and was then dried over sodium sulfate, filtered and concentrated. The crude mesylate product was then dissolved in dry DMF (70 mL) and sodium azide (5.2 g, 80 mmol) was added. The mixture was heated with stirring at 80° C. for 2 h. The cooled reaction mixture was concentrated and the residue was partitioned between ethyl acetate and brine. The organic layer was separated and washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant) to afford (S)-methyl 1-azidopropan-2-ylcarbamate. MS m/z 159.1 (M+1).

1. extractionwas then extracted with ethyl acetate
2. washThe organic layer was washed with 1N sodium hydroxide solution and brine
3. dry with materialwas then dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. dissolutionThe crude mesylate product was then dissolved in dry DMF (70 mL)
7. temperatureThe mixture was heated
8. stirringwith stirring at 80° C. for 2 h
9. customThe cooled reaction mixture
10. concentrationwas concentrated
11. customthe residue was partitioned between ethyl acetate and brine
12. customThe organic layer was separated
13. washwashed with brine
14. dry with materialdried over sodium sulfate
15. filtrationfiltered
16. concentrationconcentrated
17. customThe residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant)