反应详情

To a cooled (internal temperature of <13° C.) mixture of 3-amino-2-chloro-4-methylpyridine (10.14 g, 71.1 mmol, Matrix) and potassium acetate (9.02 g, 92 mmol) in AcOH (200 mL) was added a solution of sodium nitrite (7.36 g, 107 mmol) in water (30 mL) dropwise while maintaining an internal temperature <13° C. The reaction was allowed to warm slowly to rt and stirred for 66 h. The mixture was concentrated under reduced pressure and the residue was basified with saturated NaHCO3. The solid was filtered and washed with water. The solid was stirred over EtOAc overnight and filtered. The filtrate was combined with the organic extracts, evaporated onto silica gel and purified by flash chromatography (Isco (120 gram)) eluting with EtOAc:hexanes (0:1→1:1) to give a white crystalline solid (4.99 g, 46%). MS m/z=153.9, 155.9 [M+H]+. Calculated for C6H4ClN3: 153.

1. temperatureTo a cooled
2. temperaturewhile maintaining an internal temperature <13° C
3. concentrationThe mixture was concentrated under reduced pressure
4. filtrationThe solid was filtered
5. washwashed with water
6. stirringThe solid was stirred over EtOAc overnight
7. filtrationfiltered
8. customevaporated onto silica gel
9. custompurified by flash chromatography (Isco (120 gram))
10. washeluting with EtOAc:hexanes (0:1→1:1)