Triethylamine → tert-butyl ((S)-1-{2-[5-fluoro-3-(4-methoxyphenyl)-4-oxo-8-propoxy-4H-quinolin-1-yl]ethylcarbamoyl}-2-hydroxyethyl)carbamate

Participants

Reaction Steps

A DMF solution (0.5 ml) of N-(tert-butoxycarbonyl)-L-serine (174 mg, 0.85 mmol), triethylamine (198 mg, 1.96 mmol), diethyl phosphorocyanidate (DEPC, 176 mg, 0.97 mmol) and DMF (0.5 ml) were sequentially added to a DMF solution (1 ml) of 1-(2-aminoethyl)-5-fluoro-3-(4-methoxyphenyl)-8-propoxy-1H-quinolin-4-one (300 mg, 0.81 mmol) while ice-cooling, and stirred at room temperature for 20 hours. Water was added to the reaction mixture and then subjected to extraction using ethyl acetate. The thus-obtained organic layer was washed with an aqueous saturated sodium chloride solution twice. The washed product was dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The residue was purified using silica gel column chromatography (dichloromethane:methanol=40:1→30:1). The purified product was concentrated to dryness under reduced pressure, giving a white amorphous solid of tert-butyl ((S)-1-{2-[5-fluoro-3-(4-methoxyphenyl)-4-oxo-8-propoxy-4H-quinolin-1-yl]ethylcarbamoyl}-2-hydroxyethyl)carbamate (338 mg, yield: 75%).

Provenance & Evidence