Hydrochloric Acid → 1-(alpha-methylbenzyl)-3-(2-(4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl-amino)piperidin-1-yl)ethyl)-3-phenylpyrrolidine

Participants

Reaction Steps

According to the method of J. Am. Chem. Soc., 93, 2897 (1971), combine acetophenone (10 mmol) and 3-(2-(4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl-amino)piperidin-1-yl)ethyl)-3-phenylpyrrolidine hydrochloric acid salt (prepared from (−)-3-phenyl-3-(2-hydroxyethyl)pyrrolidine (R,R)-di-p-anisoyltartaric acid salt) (10 mmol) in methanol (100 mL). Add bromocreosol green (0.5% by weight in methanol, 1 drop). Add dropwise, a solution of sodium cyanoborohydride (10 mL, 1M in tetrahydrofuran, 10 mmol) and at the same time maintain the pH of the reaction mixture, as indicated by a yellow color for the indicator, by the addition of a 5 M solution of hydrochloric acid in methanol. When the reaction is complete, concentrate the reaction mixture in vacuo to obtain a residue. Dilute the residue with ethyl acetate and extract with water. Separate the layers, dry the organic layer over MgSO4, filter, and evaporate in vacuo to give the title compound.

Provenance & Evidence