Triethylamine → tert-butyl 1-{7-[2-(benzyloxy)phenyl]-2-oxo-1,4-dihydro-2H-pyrido[2,3-d][1,3]oxazin-5-yl}-2-phenylethylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a cold (0° C.) solution of tert-butyl 1-[2-amino-6-[2-(benzyloxy)phenyl]-3-(hydroxymethyl)-4-pyridinyl]-2-phenylethylcarbamate (0.210 g, 0.400 mmol) in THF (3.0 mL) including triethylamine (0.167 mL, 1.199 mmol) was added dropwise a solution of triphosgene (0.059 g, 0.200 mmol) in THF (1.0 mL). After stirred at 0° C. for 45 min, the mixture was allowed to warm to room temperature, and the stirring was continued for 30 min. The reaction mixture was cooled at 0° C., and then quenched with saturated aqueous NaHCO3 solution. The resulting mixture was extracted with ethyl acetate and water. The separated organic phase was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (hexane:ethyl acetate, 2:1) to give tert-butyl 1-{7-[2-(benzyloxy)phenyl]-2-oxo-1,4-dihydro-2H-pyrido[2,3-d][1,3]oxazin-5-yl}-2-phenylethylcarbamate as a colorless oil (0.170 g, yield; 77%).

Provenance & Evidence