1-Phenylpiperazine → (Piperidin-4-yl)methyl 4-phenylpiperazine-1-carboxylate

Participants

Reaction Steps

(1-(tert-Butoxycarbonyl)piperidin-4-yl)methyl 4-nitrophenyl carbonate (Intermediate 2; 5.0 g, 13.1 mmol) was dissolved in DMF (30 mL). DIPEA (4.58 mL, 26.3 mmol) and 1-phenylpiperazine (2.01 mL, 13.1 mmol) were added. The reaction mixture was stirred at room temperature for 18 h and then concentrated in vacuo. The residue was dissolved in EtOAc (300 mL) and then washed sequentially with sat aq NaHCO3 solution (6×200 mL), 10% citric acid solution (50 mL) and brine (50 mL). The solution was dried (MgSO4) and concentrated in vacuo. The residue was dissolved in DCM (20 mL) and TFA (10 mL) was added. The reaction mixture was stirred at room temperature for 3 hours and then concentrated in vacuo. The residue was dissolved in water (20 mL), sat aq NaHCO3 solution (100 mL) was added and the aqueous layer was extracted with DCM (3×200 mL). The combined organic layers were then washed with brine (50 mL), dried (MgSO4) and the solution was concentrated in vacuo to give (piperidin-4-yl)methyl 4-phenylpiperazine-1-carboxylate (3.825 g, 95.9% yield) as a yellow solid.

Provenance & Evidence