Triethylamine → Naloxone

Participants

Reaction Conditions

Reaction Steps

Into a round bottom flask equipped with a stir bar was charged noroxymorphone (2.89 g, 10.1 mmol), triethylamine (4.20 mL, 30.1 mmol), toluene (50 mL), tetrakis(triphenylphosphine)palladium[0](1.15 g, 1.00 mmol), and allyl acetate (1.40 mL, 12.9 mmol). The flask was equipped with a reflux condenser and the resulting reaction mixture was stirred and heated at 80° C. for 64 hours. The mixture was cooled to a temperature of about 20° C. and filtered through a plug of CELITE. The filtrate was concentrated under reduced pressure. The concentrated material was dissolved in a mixture of ethyl acetate (150 mL) and 0.75N aqueous hydrochloric acid (100 mL) and allowed to stir at a temperature of about 20° C. for 20 minutes. The layers were separated and the aqueous layer was washed with an additional 150 mL of ethyl acetate. The aqueous layer was basified to a pH of 9.05 with 28% ammonium hydroxide and extracted twice with dichloromethane (100 mL for each extraction). The organic portions were combined and concentrated under reduced pressure. Naloxone (HPLC purity of 76%) was isolated as an oil, contaminated with triphenylphosphine and 3-allyl-naloxone (isolated 2.78 g crude of 76% purity containing about 6.37 mmol of naloxone)).

Provenance & Evidence