反应详情

Under a nitrogen atmosphere, a solution of tert-butyl 2-(2-aminoethoxy)ethylcarbamate (2 3.1 g, 113 mmol) in N,N-dimethylformamide (100 mL) was added over a 1 hour period to a solution of 2,4-dichloro-5,6-dimethyl-3-nitropyridine (25.02 g, 113 mmol) in N,N-dimethylformamide (400 mL) containing triethylamine (24 mL, 175 mmol). The reaction mixture was allowed to stir at ambient temperature overnight. The N,N-dimethylformamide was removed under reduced pressure. The residue was dissolved in ethyl acetate (500 mL), washed with water (3×100 ml), dried over magnesium sulfate, and then concentrated under reduced pressure. The residue was purified by column chromatography (450 g of silica gel eluting sequentially with 3/1 hexanes/ethyl acetate (1.2 L), 2/1 hexanes/ethyl acetate (1.2 L), and 1/1 hexanes/ethyl acetate (1 L)) to provide 20.67 g of tert-butyl 2-{2-[(2-chloro-5,6-dimethyl-3-nitropyridin-4-yl)amino]ethoxy}ethylcarbamate.

1. customThe N,N-dimethylformamide was removed under reduced pressure
2. dissolutionThe residue was dissolved in ethyl acetate (500 mL)
3. washwashed with water (3×100 ml)
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by column chromatography (450 g of silica gel eluting sequentially with 3/1 hexanes/ethyl acetate (1.2 L), 2/1 hexanes/ethyl acetate (1.2 L), and 1/1 hexanes/ethyl acetate (1 L))