反应详情

温度

50 °C

4-(2-Methanesulfonyloxymethylphenyl)piperidine-1-carboxylic acid t-butyl ester (27.0 g, 60.6 mmol, 1.0 eq.) was dissolved in MeCN (540 mL) and added to K2CO3 (25 g, 180 mmol, 3.0 eq.) and 2,4,6-trifluorophenol (13.5 g, 90.9 mmol, 1.5 eq.). The mixture was vigorously stirred at 50° C. for 6 hours, removed from the heat, and stirred overnight. The mixture was cooled at room temperature, and diluted with EtOAc (700 mL) and water (700 mL). The phases were separated, and the organic layer was washed twice with 1.0 M NaOH in water (2×400 mL) and saturated aqueous NaCl (1×400 mL), then dried over Na2SO4 and the solvent removed to yield crude 4-[2-(2,4,6-trifluorophenoxymethyl)-phenyl]piperidine-1-carboxylic acid t-butyl ester (25.0 g). The crude product was combined with smaller scale runs for a total of 30 g, and purified by chromatography (0-10% EtOAc in hexanes) to yield 4-[2-(2,4,6-trifluorophenoxymethyl)phenyl]piperidine-1-carboxylic acid t-butyl ester (22.0 g). The t-butyl ester (22.0 g, 31.3 mmol, 1.0 eq.) was combined with 1.25M HCl in EtOH (250 mL, 310 mmol, 10.0 eq.). The mixture was stirred at room temperature for 8 hours, then stored at −10° C. over approximately 48 hours. Most of solvent was removed by rotary evaporation. To the resulting thick slurry was added EtOAc (80 mL), followed by stirring at room temperature for 2 hours. First crop was isolated by filtration, and the filter cake was washed with EtOAc (20 mL) and dried to yield the title compound as a hydrochloride salt (8.5 g, >99% purity) white solid. HPLC of the filtrate shows ˜25% area of product. For the second crop, the solvent was removed by rotary evaporation and the resulting solid (˜10 g) was slurried in EtOAc (40 mL), first at room temperature, then at 60° C., and again at room temperature to yield the title compound as a hydrochloride salt (1.7 g, >99% purity).

1. customremoved from the heat
2. stirringstirred overnight
3. temperatureThe mixture was cooled at room temperature
4. additiondiluted with EtOAc (700 mL) and water (700 mL)
5. customThe phases were separated
6. washthe organic layer was washed twice with 1.0 M NaOH in water (2×400 mL) and saturated aqueous NaCl (1×400 mL)
7. dry with materialdried over Na2SO4
8. customthe solvent removed
9. customto yield crude 4-[2-(2,4,6-trifluorophenoxymethyl)-phenyl]piperidine-1-carboxylic acid t-butyl ester (25.0 g)
10. custompurified by chromatography (0-10% EtOAc in hexanes)