HCID 19968447, compound → HCID 19968433, compound

Participants

Reaction Steps

5-(3-Chlorophenyl)-5-hydroxy-1-azaspiro[5.5]undecane (2.5 g, prepared as described in Example D) was dissolved in concentrated sulphuric acid (35 ml) and stirred at ambient temperature for 2 hours. The mixture was then poured cautiously onto ice (100 ml) and the resulting white precipitate was collected by filtration and suspended in ethyl acetate (300 ml). 5M Aqueous sodium hydroxide solution (250 ml) was added and the mixture was stirred at ambient temperature for 15 minutes. The aqueous layer was separated and extracted with ethyl acetate (2×200 ml), then the combined organic solutions were washed with water, dried over magnesium sulphate and the solvent removed in vacuo. The resulting oil was dissolved in ether (100 ml), charcoal (1 g) was added, and the mixture was heated under reflux for 5 minutes and hot-filtered. The cooled filtrate was saturated with hydrogen chloride and the resulting solid collected, washed with ether and dried in vacuo at ambient temperature to give 5-(3-chlorophenyl)-1-azaspiro[5.5]undec-4-ene hydrochloride as a white solid. Yield 2.1 g, mp 281°-282° C. (dec).

Provenance & Evidence