Methyl iodide → tert-Butyl 3,3-dimethyl-4-oxopiperidine-1-carboxylate

Temperature

0 °C

4-Oxo-piperidine-1-carboxylic acid tert-butyl ester (5 g, 25 mmol) was dissolved in tetrahydrofuran (100 mL) and the resulting solution was cooled to 0° C. Sodium hydride (60% in mineral oil, 2.10 g, 53 mmol) was added to the cooled solution in a single portion, and the resulting cloudy mixture was allowed to stir 10 min. Methyl iodide was subsequently added and the mixture was allowed to warm to room temperature over several hours. Stirring continued over night (12 h). The light orange mixture was concentrated under reduced pressure. The residue was partitioned between ether and water. The aqueous phase was back-extracted with additional ether. The combined extracts were washed with water and brine, dried over sodium sulfate, filtered and concentrated to a pale yellow solid. The solid was triturated with 4% ethyl acetate in hexanes (50 mL) to afford 3,3-dimethyl-4-oxo-piperidine-1-carboxylic acid tert-butyl ester as a cream-colored solid (1.8 g, 32%).

1. temperatureto warm to room temperature over several hours
2. stirringStirring
3. waitcontinued over night
4. custom(12 h)
5. concentrationThe light orange mixture was concentrated under reduced pressure
6. customThe residue was partitioned between ether and water
7. extractionThe aqueous phase was back-extracted with additional ether
8. washThe combined extracts were washed with water and brine
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated to a pale yellow solid
12. customThe solid was triturated with 4% ethyl acetate in hexanes (50 mL)

ORD record

ord-0f09a2bb51314285b6f991b9d512a73d

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07727985B2