phosphenous acid → 1-Phenyl-4-piperidinone

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(4-amino-phenyl)-piperidin-4-one (1.34 g, 7.05 mmol) in 50% hydrochloric acid (10 mL) was stirred at ambient temperature for 15 min. The reaction mixture was cooled to 0° C. and a solution of sodium nitrite (1.46 g) in water (5 mL) added and stirred for 30 min. To this reaction mixture was added cold 30-32% hypophosphorus acid (10 mL), the mixture then being warmed to ambient temperature and stirred for 2 h. The reaction mixture was neutralised with saturated sodium bicarbonate solution and extracted with ethyl acetate. The organic layer was washed with water, brine solution, dried over anhydrous sodium sulfate and concentrated to give a residue which was purified by column chromatography over silica gel (60-120 mesh) using 17% ethyl acetate in petroleum ether as eluent to afford 1-phenyl-piperidin-4-one (0.18 g, 15%) as a liquid.

Provenance & Evidence