反应详情

温度

50 °C

A 50 mL round bottom flask set up with a reflux condenser under nitrogen atmosphere was charged 4-azabenzimidazole N-oxide (1.2 g, 8.88 mmol) and 11 mL of DMF. This was heated to 50° C. and methanesulfonyl chloride (1.86 ml, 23.98 mmol) was added dropwise via syringe. The resulting mixture was heated to 80° C. and stirred at this temperature for 16 hours. This was cooled to room temperature and quenched with water (approximately 10 mL) and reaction mixture brought to pH 7 by adding 6N NaOH aqueous solution. The reaction was extracted four times with dichloromethane (50 mL). Some product was present in aqueous layer; this was concentrated and residue set aside. The combined organic layers were dried with sodium sulfate, filtered, and concentrated. The material was purified via column chromatography (RediSep 40 g column, gradient elution 0-10% MeOH:DCM) to afford 7-chloro-3H-imidazo[4,5-b]pyridine (450 mg, 33.0% yield). MS [M+H]=154.2. Calc'd C6H4ClN3=153.56.

1. customA 50 mL round bottom flask set up with a reflux condenser under nitrogen atmosphere
2. temperatureThe resulting mixture was heated to 80° C.
3. temperatureThis was cooled to room temperature
4. customquenched with water (approximately 10 mL) and reaction mixture
5. additionby adding 6N NaOH aqueous solution
6. extractionThe reaction was extracted four times with dichloromethane (50 mL)
7. concentrationthis was concentrated
8. dry with materialThe combined organic layers were dried with sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customThe material was purified via column chromatography (RediSep 40 g column, gradient elution 0-10% MeOH:DCM)