反应详情

In a 250 mL round-bottomed flask at 0° C. under nitrogen was added methyl 4-methoxybenzoate (Aldrich, 3.32 g, 20.00 mmol) and 4-bromo-2-methylpyridine (Frontier, 1.72 g, 10.00 mmol) in anhydrous tetrahydrofuran (40.0 mL) to give a yellow solution. Lithium hexamethyldisilazide (1 M in tetrahydrofuran, 20 mL, 20 mmol) was added dropwise over 15 minutes via a dropping addition funnel to produce an orange transparent solution that was stirred for 18 hours at ambient temperature. The mixture was partitioned between ethyl acetate and water. The organic layer was washed with brine, dried (Na2SO4), filtered and concentrated to a reddish oil. Purification by flash chromatography on a silica 80 g cartridge eluting with 10-60% ethyl acetate in hexane gave the title compound (2.68 g, 88%). MS (APCI+) m/z 306/308 (M+H)+.

1. customto give a yellow solution
2. customto produce an orange transparent solution
3. customThe mixture was partitioned between ethyl acetate and water
4. washThe organic layer was washed with brine
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated to a reddish oil
8. customPurification by flash chromatography on a silica 80 g cartridge
9. washeluting with 10-60% ethyl acetate in hexane