p-Toluenesulfonic acid → HCID 68242309, compound

(cis)-tert-butyl-spiro[1,3-dioxolane-2,6′-3,4,4a,5,7,7a-hexahydro-1H-cyclopenta[c]pyridine]-2′-carboxylate 14g (620 mg, 2.20 mmol) was dissolved in 50 mL of acetone followed by the addition of p-toluenesulfonic acid (200 mg, 1.10 mmol). The resulting solution was heated to reflux for 30 minutes, then cooled down to room temperature, added dropwise with saturated sodium bicarbonate solution to adjust pH to 8 to 9, extracted with dichloromethane (50 mL×3). The combined organic phase was washed with saturated sodium chloride solution (50 mL×3), then dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to obtain the title compound (cis)-tert-butyl-6-oxo-3,4,4a,5,7,7a-hexahydro-1H-cyclopenta[c]pyridine-2-carboxylate 14h (450 mg, yield: 85.0%) as a colorless oil liquid.

1. temperatureThe resulting solution was heated
2. temperatureto reflux for 30 minutes
3. extractionextracted with dichloromethane (50 mL×3)
4. washThe combined organic phase was washed with saturated sodium chloride solution (50 mL×3)
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationthe filtrate was concentrated under reduced pressure
8. customThe resulting residue was purified by silica gel column chromatography

ORD record

ord-01fb10ae309049298ba3d7bd249b8493

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08691822B2