Hydrochloric Acid → 1-Benzyl-4-(1,3-dihydroxyprop-2-ylamino)-piperidine

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Reaction Steps

2.75 g of 2-aminopropane-1,3-diol and 5.9 g of 1-benzyl-4-piperidone are dissolved in 60 ml of methylene chloride and a total of 9.9 g of sodium triacetoxyborohydride are added batchwise while cooling with ice. The mixture is left to stand overnight at ambient temperature. 60 ml of methylene chloride and some water are added, then conc. hydrochloric acid is added while cooling with ice until an acidic reaction is obtained. The mixture is stirred for about another 15 min. while cooling and then made significantly alkaline with 4 N sodium hydroxide solution. The aqueous phase is separated off, the organic phase is washed with a very little water, dried over sodium sulphate and the solvent is eliminated in vacuo. 8 g of substance are obtained which are chromatographed with methylene chloride/methanol 8:2 over 150 g of silica gel. The fractions found to be uniform by TLC are combined and the solvent is eliminated in vacuo. 7.3 g of 1-benzyl-4-(1,3-dihydroxyprop-2-ylamino)-piperdine are obtained.

Provenance & Evidence