反应详情

To a solution containing −490 mg (2.71 mmol) of 1,4,6-Trimethyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine in 7.2 mL of THF was added 2.70 mL (4.34 mmol) of n-BuLi (1.6 M in hexanes) followed by 4504 (509 mg, 2.85 mmol) of 1-bromoheptane at −78° C. The reaction mixture was slowly warmed to room temperature and stirred for 16 h. The reaction mixture was quenched by the addition of 25 mL of sat aq. NH4Cl at 0° C. The mixture was extracted with three 40-mL portions, of EtOAc. The combined organic layer was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated under diminished pressure. The residue was purified via flash chromatography on a silica gel column (42×2.5 cm). Step gradient elution with 1:10→1:4 ethyl acetate-hexanes as eluent gave 1,4-dimethyl-6-octyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine as a yellow oil: yield 402 mg (57%); silica gel TLC Rf 0.36 (8:1:1 hexanes-ethyl acetate-methanol); 1H NMR (CDCl3) δ 0.79 (t, 2H, J=7.2 Hz), 1.16-1.30 (m, 10H), 1.58 (quint, 2H, J=8.0 Hz), 2.00 (s, 3H), 2.48 (t, 2H, J=8.0 Hz), 2.72 (t, 2H, J=8.4 Hz), 2.82 (s, 3H), 3.38 (t, 2H, J=8.4 Hz), 6.14 (s, 1H).

1. customThe reaction mixture was quenched by the addition of 25 mL of sat aq. NH4Cl at 0° C
2. extractionThe mixture was extracted with three 40-mL portions, of EtOAc
3. washThe combined organic layer was washed with brine
4. dry with materialdried over anhydrous MgSO4
5. filtrationfiltered
6. concentrationconcentrated under diminished pressure
7. customThe residue was purified via flash chromatography on a silica gel column (42×2.5 cm)
8. washStep gradient elution with 1:10→1:4 ethyl acetate-hexanes as eluent