反应详情

温度

-78 °C

To a stirred solution of 2-bromo-4-methylpyridine (Compound 15) (20.20 g, 117.4 mmol) in THF (250 mL) at −78° C. was added LDA (2.0 M THF/Hex, 70.5 mL, 141 mmol) dropwise over 10 min. The solution was stirred at −78° C. for 35 min. Then a solution of N-methoxy-N-methyl acetamide (14.5 g, 141 mmol) in THF (30 mL) was added dropwise over 10 min. After 15 min. at −78° C., the solution was warmed to 0° C. and stirred for 1 h. The solution was poured into H2O (250 mL), extracted with Et2O (3×250 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 20% EtOAc-hexanes) provided the title compound (16.75 g, 78.2 mmol, 67%).

1. waitAfter 15 min. at −78° C.
2. temperaturethe solution was warmed to 0° C.
3. stirringstirred for 1 h
4. extractionextracted with Et2O (3×250 mL)
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated