反应详情

To a solution of 7-chloro-imidazo[1,2,a]pyridine (6.10 g, 40 mmol) (Yamanaka, Motosuke et al., Chemical & Pharmaceutical Bulletin (1991), 39(6), 1556-67) in dry acetonitrile (100 mL), add N-iodosuccinamide. Stir for 30 minutes. Filter off the precipitate and then wash with acetonitrile. Recrystallize the precipitate from acetonitrile to give a white solid. Concentrate the filtrate, dilute with ethyl acetate, wash with 10% sodium hydrogensulfite (NaHSO3), saturated aqueous sodium bicarbonate, saturated aqueous NaCl, dry over MgSO4, filter and evaporate. Use the combined solid without further purification (8.0 g, 73%). 1H NMR (DMSO) δ 8.33 (d, 1H, J=7.3 Hz), 7.79 (d, 1H, J=2.0 Hz), 7.72 (s, 1H), 7.07 (dd, 1H, J=7.3 and 2.0 Hz).

1. filtrationFilter off the precipitate
2. washwash with acetonitrile
3. customRecrystallize the precipitate from acetonitrile
4. customto give a white solid
5. concentrationConcentrate the filtrate
6. additiondilute with ethyl acetate
7. washwash with 10% sodium hydrogensulfite (NaHSO3), saturated aqueous sodium bicarbonate, saturated aqueous NaCl
8. dry with materialdry over MgSO4
9. filtrationfilter
10. customevaporate
11. customwithout further purification (8.0 g, 73%)