反应详情

To a solution of 2-chloronicotinic acid (7.88 g), N-benzyl-2-{[tert-butyl(dimethyl)silyl]oxy}ethanamine (13.3 g) synthesized by known method (e.g., the method described in WO99/31085) and HOBt-H2O (11.5 g) in DMF (50 mL) was added WSC.HCl (14.4 g), and the mixture was stirred at room temperature for 14 hr. The reaction mixture was poured into water, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogen carbonate solution and brine, and concentrated. The residue was purified by silica gel column chromatography (solvent gradient; 10→33% ethyl acetate/hexane) to give N-benzyl-N-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-2-chloronicotinamide (11.8 g, 58%) as a colorless oil.

1. extractionthe mixture was extracted with ethyl acetate
2. washThe organic layer was washed with saturated aqueous sodium hydrogen carbonate solution and brine
3. concentrationconcentrated
4. customThe residue was purified by silica gel column chromatography (solvent gradient; 10→33% ethyl acetate/hexane)