反应详情

Add slowly butyllithium (1.088 mL, 1.741 mmol, 1.6M solution in hexane) to a solution of 2-bromo-5-tert-butoxycarbonylaminomethyl-pyridine (200 mg, 0.696 mmol) in anhydrous THF (10 mL) at −78° C. Stir the mixture at this temperature for 35 min. Add 3,3-dimethylbutyraldehyde (0.219 mL, 1.741 mmol) and stir the mixture at −78° C. for 3 h. Quench the reaction mixture at −78° C. with brine. Extract the aqueous phase with EtOAc (3×15 mL). Dry the combined organic extracts over Na2SO4, filter and concentrate in vacuo. Purify The crude mixture by chromatography on silica gel eluting with hexane and hexane/EtOAc (3:2) to afford the desired intermediate as a colorless oil (118 mg, 55%). MS (ES+) m/z: 309 (M+H)+.

1. customQuench the reaction mixture at −78° C. with brine
2. extractionExtract the aqueous phase with EtOAc (3×15 mL)
3. dry with materialDry the combined organic extracts over Na2SO4
4. filtrationfilter
5. concentrationconcentrate in vacuo
6. customPurify The crude mixture by chromatography on silica gel eluting with hexane and hexane/EtOAc (3:2)