Hydrochloric Acid → 1-{[(9H-fluoren-9-yl)methoxy]carbonyl}-4-methylpiperidine-3-carboxylic acid

温度

60 °C

To a solution of 1-(tert-butoxycarbonyl)-4-methylpiperidine-3-carboxylic acid (1.50 g, 6.17 mmol, Example #13, Step G) in 1,4-dioxane (10 mL) was added aqueous HCl (4N in 1,4-dioxane (4.62 mL, 18.5 mmol). The reaction mixture was heated at about 60° C. for about 16 h before being allowed to cool to ambient temperature. To the mixture was added NaHCO3 (2.07 g, 24.7 mmol) and water (10.0 mL) followed by (9H-fluoren-9-yl)methyl 2,5-dioxopyrrolidin-1-yl carbonate (4.16 g, 12.3 mmol). The reaction was stirred at about 25° C. for about 16 h. The reaction was acidified to about pH 1 with aqueous 1N HCl and was extracted with EtOAc (75 mL). The organic layer was washed with brine (50 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The product was purified by silica gel chromatography (40 g column) eluting with a gradient of 1-5% MeOH in DCM to give 1-(((9H-fluoren-9-yl)methoxy)carbonyl)-4-methylpiperidine-3-carboxylic acid (0.72 g, 31%) as a clear oil: LC/MS (Table 2, Method a) Rt=2.44 min; MS m/z: 366 (M+H)+.

1. temperatureto cool to ambient temperature
2. extractionwas extracted with EtOAc (75 mL)
3. washThe organic layer was washed with brine (50 mL)
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe product was purified by silica gel chromatography (40 g column)
8. washeluting with a gradient of 1-5% MeOH in DCM

ORDレコード

ord-c0e2492d7f5b4d8293cf631feb7415e2

出典データセット

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08962629B2