Sodium borohydride → HCID 23312292, compound

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Reaction Steps

A solution of 6.0 g of sodium borohydride in 25 ml of water is added dropwise, with stirring and external cooling, to a solution of 6.0 g of 1-(3-oxobutyl)-4-(2-benzofuranyl)-piperidine (cp. Example 8), the manner of addition being such that the reaction temperature does not exceed 30°. The mixtuure is subsequently stirred for 15 hours at room temperature. The methanol is then evaporated off in vacuo, the aqueous phase remaining behind extracted twice with 250 ml of chloroform each time, the chloroform solution dried over sodium sulphate, filtered, and concentrated by evaporation. The residue is dissolved in 500 ml of 2 N hydrochloric sacid, and the acid solution washed with ether. The aqueous solution is subsequently 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 1-(3-hydroxybutyl)-4-(2-benzofuranyl)-piperidine (4-(2 -benzofuranyl)-α-methyl-1-piperidine-propanol). The hydrochloride of this is prepared with hydrogen chloride in ethyl acetate, and recrystallised from ethyl acetate, whereupon it melts at 194°-195°.

Provenance & Evidence