Tetrahydrofuran → 4-({[3-({(tert-butoxycarbonyl)[(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-(2-fluorophenyl)piperidin-1-yl]carbonyl}oxy)benzoic acid

Participants

Reaction Steps

To a mixture of 192 mg of tert-butyl {[4-(2-fluorophenyl)piperidin-3-yl]methyl}[(1R)-1-(1-naphthyl)ethyl]carbamate and 157 mg of sodium hydrogen carbonate were added 3 mL of THF and 1.5 mL of water, followed by addition of 133 mg of methyl 4-[(chlorocarbonyl)oxy]benzoate (Fluka). It was stirred at room temperature for 1 hour, and then extracted with ethyl acetate. The organic layer was washed with water and saturated brine in this order, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and to 327 mg of the obtained residue were added 4 mL of THF, 2 mL of methanol, and 2.5 mL of a 1 M aqueous sodium hydroxide solution, followed by stirring at room temperature overnight. The reaction mixture was neutralized by addition of 2.6 mL of 1 M hydrochloric acid, concentrated under reduced pressure, and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate, and then filtered, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (chloroform-methanol) to obtain 228 mg of 4-({[3-({(tert-butoxycarbonyl)[(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-(2-fluorophenyl)piperidin-1-yl]carbonyl}oxy)benzoic acid as a colorless foamy substance. ESI+: 627

Provenance & Evidence