Ammonium Chloride → 1-Boc-4-Methylenepiperidine

Temperature

0 °C

Methyltriphenylphosphonium bromide (11.7 g, 32.7 mmol) was suspended in tetrahydrofuran (50 mL), and the suspension was cooled to 0° C. Potassium tert-butoxide (3.61 g, 37.6 mmol) was added, and the mixture was stirred for 1 hr. To the mixture was added dropwise a solution (25 mL) of tert-butyl 4-oxopiperidine-1-carboxylate (5.02 g, 25.2 mmol) in tetrahydrofuran, and the mixture was stirred for 2.5 hr with warming to room temperature. To the reaction mixture was added aqueous ammonium chloride solution (100 mL), and the mixture was extracted with a mixture of diethyl ether/ethyl acetate=1/1 (200 mL×2). The organic layers were combined, washed with saturated brine (50 mL), and dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=100/0→90/10) to give the title compound (4.71 g, 95%) as a colorless oil.

1. stirringthe mixture was stirred for 2.5 hr
2. temperaturewith warming to room temperature
3. extractionthe mixture was extracted with a mixture of diethyl ether/ethyl acetate=1/1 (200 mL×2)
4. washwashed with saturated brine (50 mL)
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=100/0→90/10)

ORD record

ord-7093d403714744e49acd5986b65ecc65

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08344135B2