L-Tartaric acid → HCID 178526011, compound

Participants

Reaction Steps

To a stirred mixture of anhydrous ammonium formate (15.8 g, 0.25 mol) and trans-(S)-2-{(R)-2-[4-(benzyloxyethyl)cyclohexyl]pyrrolidin-1-yl}-2-phenylethanol (20.5 g, 0.050 mol) in MeOH (200 mL) is added 10% palladium on carbon (1.00 g), and the resulting mixture is stirred under nitrogen atmosphere at room temperature for 2 hours and then at 35° C. for 3 hours. The reaction mixture is filtered, and the filtrate is concentrated. The crude residue is dissolved with 1N HCl and extracted with ether to remove phenethylalcohol. The water layer is neutrized by addition of 2.5 N NaOH and extracted with CH2Cl2. The combined organic layer is washed with brine, dried over magnesium sulfate, filtered and concentrated to give crude trans-(R)-2-[4-(benzyloxyethyl)cyclohexyl]pyrrolidine. To the mixture of crude trans-(R)-2-[4-(benzyloxyethyl)cyclohexyl]pyrrolidine in EtOH (65 mL), L-tartaric acid (7.60 g, 0.050 mol) is added. The resulting mixture is warmed to 60° C., then cooled slowly to room temperature. The precipitate is filtered and rinsed with additional EtOH to afford trans-(R)-2-[4-(benzyloxyethyl)cyclohexyl]pyrrolidine tartaric acid salt as off-white crystal. The tartaric acid salt is dissolved in 1N NaOH aq. and extracted with CH2Cl2, and the organic layer is dried over magnesium sulfate, filtered, and evaporated to afford pure trans-(R)-2-[4-(benzyloxyethyl)cyclohexyl]pyrrolidine.

Provenance & Evidence