反应详情

温度

90 °C

2-Bromo-1,1-diethoxypropane (5g) was added to a stirring solution of aq. 1N HCl (15 mL) and heated at 90° C. for 1 h. The clear reaction mixture was cooled to room temperature and treated with solid NaHCO3 till pH 7.0. 2-amino-5-bromopyridine (1.8 G) and MeOH (25 mL) were transferred successively to the above reaction mixture and heated at 90° C. After 8 h, the reaction mixture was concentrated under vacuum by rotary evaporator. The resulting solid concentrate was stirred in CH2Cl2/water (200 mL/75 ml). Organic layer was separated, dried over MgSO4, filtered and concentrated. The crude concentrate was stirred in EtOAc (30 mL) and the solid was collected by filtration to obtain 6-bromo-3-methylimidazo[1,2-a]pyridine as a tan solid (1.6 g). 1H NMR (300 MHz, DMSO-d6): δ 8.55 (s, 1H), 7.50 (d, J=9.5 Hz, 1H), 7.37 (s, 1H), 7.28 (d, J=9.5 Hz, 1H), 2.44 (s, 3H).

1. temperatureThe clear reaction mixture was cooled to room temperature
2. temperatureheated at 90° C
3. concentrationthe reaction mixture was concentrated under vacuum by rotary evaporator
4. concentrationThe resulting solid concentrate
5. customOrganic layer was separated
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. concentrationThe crude concentrate
10. stirringwas stirred in EtOAc (30 mL)
11. filtrationthe solid was collected by filtration