反应详情

A mixture of 2,6-dichloro-3-carboxypyridine (5.73 g, 30 mmole) and N-methylmorpholine (3.6 ml, 33 mmole) in dichloromethane (100 ml) was stirred in an ice-bath for 5 min. Isopropyl chloroformate (4.28 ml, 33 mmole) was added the reaction mixture at 0° C. The reaction mixture was stirred for 30 min and then bubbled with pure ammonia gas for 2 min. and stirred overnight at room temperature. The crude was concentrated under reduced pressure and sodium bisulfate (0.5M, 35 ml) was added with stirring. The aqueous solution was extracted with ethyl acetate (3×40 ml). The organics was washed with water and brine and dried with sodium sulfate to give yellow crude product (6.3 g, 50% pure).

1. stirringThe reaction mixture was stirred for 30 min
2. custombubbled with pure ammonia gas for 2 min.
3. stirringstirred overnight at room temperature
4. concentrationThe crude was concentrated under reduced pressure and sodium bisulfate (0.5M, 35 ml)
5. additionwas added
6. stirringwith stirring
7. extractionThe aqueous solution was extracted with ethyl acetate (3×40 ml)
8. washThe organics was washed with water and brine
9. dry with materialdried with sodium sulfate