反应详情

Under a nitrogen atmosphere, triethylamine (47 mL, 340 mmol) was added to a solution of 2,4-dichloro-5,6-dimethyl-3-nitropyridine (30.0 g, 136 mmol) and ethyl 4-aminobutyrate hydrochloride (32 g, 190 mmol) in DMF (500 mL), and the reaction was stirred overnight. The solvent was removed under reduced pressure, and the residue was partitioned between chloroform (500 mL), water (25 mL), and brine (25 mL). The organic layer was separated and washed with water:brine (1:1, 3×50 mL), dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting orange solid was recrystallized from ethyl acetate:hexanes and dried under high vacuum to provide 21.5 g of ethyl 4-[(2-chloro-5,6-dimethyl-3-nitropyridin-4-yl)amino]butanoate.

1. customThe solvent was removed under reduced pressure
2. customthe residue was partitioned between chloroform (500 mL), water (25 mL), and brine (25 mL)
3. customThe organic layer was separated
4. washwashed with water:brine (1:1, 3×50 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe resulting orange solid was recrystallized from ethyl acetate
9. dry with materialhexanes and dried under high vacuum