反应详情

温度

80 °C

2-Ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridine (2.17 g) was added to stirred fuming sulphuric acid (7 ml) and the resulting solution was warmed to 80° C. Potassium nitrate (3.0 g) was added in portions over a period of 10 minutes and the resulting mixture was heated am between 95 and 100° C. for 10 minutes, cooled, then poured onto ice (approx. 25 g). The mixture was neutralised with concentrated aqueous ammonia solution and then extracted with dichloromethane (2×50 ml). The combined extracts were dried over magnesium sulphate and the solvent was then evaporated. Recrystallization of the resulting residue from ethyl acetate (15 ml) gave the intermediate compound 2-ethyl-5,7-dimethyl-6-nitro-3H-imidazo-[4,5-b]pyridine (1.01 g; m.p. 146°-149° C.).

1. temperaturethe resulting mixture was heated am between 95 and 100° C. for 10 minutes
2. temperaturecooled
3. additionpoured onto ice (approx. 25 g)
4. extractionextracted with dichloromethane (2×50 ml)
5. dry with materialThe combined extracts were dried over magnesium sulphate
6. customthe solvent was then evaporated
7. customRecrystallization of the resulting residue from ethyl acetate (15 ml)