Potassium Hydroxide → HCID 23312290, compound

Participants

Reaction Steps

7.8 g of 4-(naphtho[2,1-b]furan-2-yl)-1-piperidinecarboxylic acid ethyl ester is dissolved in 60 ml of ethylene glycol. After the addition of 40 ml of a 50% aqueous potassium hydroxide solution, the formed cloudy solution is heated, with vigorous stirring, for 15 hours at 160°. The reaction solution is thereupon cooled to 20° and extracted twice with 500 ml of ethyl acetate. The organic phases are washed five times with 1 liter of water each time, dried over sodium sulphate, filtered, and concentrated by evaporation. The residue is dissolved in 400 ml of 2 N hydrochloric acid, and the acid solution extracted with toluene. The aqueous solution is then adjusted by addition of 10% sodium hydroxide solution to have a pH value of 12, and extracted with 1 liter of chloroform. The chloroform solution is dried with sodium sulphate, filtered, and concentrated by evaporation to obtain crude 4-(naphtho[2,1-b]furan-2-yl)-piperidine. The hydrochloride is prepared with hydrogen chloride in ethyl acetate, and recrystallised from ethyl acetate, whereupon it melts at 225°.

Provenance & Evidence