反应详情

To a solution of 2-ethyl-imidazo[1,2-a]pyridine (2.17 g, 14.9 mmol) in EtOH (25 mL) was added Br2 (2.0 g, 12.5 mmol) in H2O (5 mL) dropwise at rt. After stirring at rt for 4 h, EtOH was evaporated under reduced pressure. The residue was basified with aqueous NaHCO3 and extracted with CH2Cl2 (3×). The organic phase was washed with brine and dried over anhydrous MgSO4. Concentration followed by flash chromatography chromatography eluting with 20% EtOAc in hexanes, followed by 50% EtOAc in hexanes afforded the title compound (1.88 g) as a viscous oil. 1H NMR (500 MHz, CDCl3): δ 1.36 (t, J=7.5 Hz, 3H), 2.83 (q, J=7.6 Hz, 2H), 6.88 (t, J=6.8 Hz, 1H), 7.20 (m, 1H), 7.55 (dd, J=8.9, 0.9 Hz, 1H), 8.05 (dd, J=6.9, 1.2 Hz, 1H).

1. customEtOH was evaporated under reduced pressure
2. extractionextracted with CH2Cl2 (3×)
3. washThe organic phase was washed with brine
4. dry with materialdried over anhydrous MgSO4
5. concentrationConcentration
6. washeluting with 20% EtOAc in hexanes