Ammonium Chloride → 1-Boc-4-Methylenepiperidine

Participants

Reaction Conditions

Reaction Steps

In a thoroughly heated apparatus flooded with protecting gas, methyltriphenyl-phosphonium bromide (53.82 g, 150 mmol) was suspended in diethyl ether (300 ml) and cooled to 0° C. Potassium tert-butylate (15.78 g, 140 mmol) was added in portions, and the suspension was stirred for 30 min. Boc-4-piperidone (20 g, 100 mmol), dissolved in diethyl ether (200 ml), was slowly added dropwise, and then the mixture was warmed to room temperature and stirred for 15 h. The reaction mixture was cooled, and ammonium chloride solution (300 ml, 10%) was added thereto; after phase separation, the aqueous phase was extracted with ether (3×200 ml), and the combined organic phases were dried (MgSO4) and concentrated in vacuo. The crude product was purified by column chromatography (silica gel) with ether/hexane (1:1). Yield: 18.57 g (93%)

Provenance & Evidence