反应详情

温度

0 °C

Normal-butyllithium (2.69 M, 157.1 mL) was dropwise added to a solution of tert-butyl 3-methylpyridin-2-ylcarbamate (40.0 g) in THF (550 mL) at an internal temperature of −40 to −20° C., followed by stirring at 0° C. for 1 hr. Subsequently, a solution of methyl iodide (28.6 g) in THF (50 mL) was dropwise added to the reaction solution at an internal temperature of −70 to −60° C., followed by stirring at −78° C. for 30 min. The reaction solution was poured into ice water, followed by extraction with ethyl acetate twice. The organic layers were combined, washed with saturated saline, and dried over anhydrous sodium sulfate. The solvent was distilled away. Hexane (300 mL) was added to the resulting residue, and the precipitate was collected by filtration and dried under reduced pressure to obtain compound (40a) (32.4 g, 76%) as a white solid.

1. stirringby stirring at −78° C. for 30 min
2. extractionfollowed by extraction with ethyl acetate twice
3. washwashed with saturated saline
4. dry with materialdried over anhydrous sodium sulfate
5. distillationThe solvent was distilled away
6. additionHexane (300 mL) was added to the resulting residue
7. filtrationthe precipitate was collected by filtration
8. customdried under reduced pressure