Formic acid (ammonium salt) → (S)-2-(4-Phenyl-butyl)-piperazine

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Reaction Steps

Combine (S)-1,4-dibenzyl-2-(4-phenyl-but-3-enyl)-piperazine (2.12 g, 5.3 mmol), 10% Pd/C (300 mg, 0.027 mmol) and ammonia formate (1.67 g, 26.5 mmol) in EtOH (50 mL), heat to reflux for 3 hours 30 minutes, and cool to room temperature. Remove the catalyst via filtration, and concentrate the filtrate to a residue. Purification by flash chromatography on silica gel using 2N NH3 in MeOH and dichloromethane (5%–15%) to give the title compound (780 mg, yield 67%): mass spectrum (Electrospray): m/z=219.2 (M+1); 1H NMR (CDCl3): δ7.30–7.15 (m, 5H), 2.96–2.55 (m, 8H), 2.37–2.30 (m, 1H), 1.64–1.60 (m, 2H), 1.39–1.29 (m, 4H).

Provenance & Evidence