反应详情

In a typical run, 400 mg of 5-methyl-2-(3-nitro-phenyl)-oxazolo[4,5-b]pyridine (1.57 mmol) was suspended in 50 mL of CCl4 along with 280 mg (1.57 mmol) of NBS and 20 mg of benzoyl peroxide. The reaction mixture was stirred under reflux for 4 hours. LC/MS showed about 50% conversion to the desired bromide. After another 2 hours of reflux, no additional change was observed. Another 1 eq of NBS was added and reflux was continued for another 4 hours. LC/MS showed complete conversion. The reaction mixture was concentrated and the resulting crude product was purified by chromatography (Isco, gradient elution, CH2Cl2 to 9:1 CH2Cl2/MeOH) to afford essentially quantitative yield of 5-bromomethyl-2-(3-nitro-phenyl)-oxazolo[4,5-b]pyridine.

1. temperatureunder reflux for 4 hours
2. temperatureAfter another 2 hours of reflux
3. temperaturereflux
4. concentrationThe reaction mixture was concentrated
5. customthe resulting crude product was purified by chromatography (Isco, gradient elution, CH2Cl2 to 9:1 CH2Cl2/MeOH)