Hydrochloric Acid → Methyl 4-Boc-piperazine-2-acetate

Participants

Reaction Steps

The 13.7 g (40 mmol) of methyl 1,4-dibenzylpiperazine-2-acetate, 150 mL of MeOH, 50 mL of 1 N HCl (aqueous) and 3 g of 10% Pd/C were combined and hydrogenated with H2 (50 psi) for 24 hours. The reaction was filtered, the filtrate was concentrated in vacuo to remove most of the MeOH, and the residue was made basic with K2CO3 to pH=9-10, and 9.8 g (40 mmol) of BOC-ON was added slowly at 0° C. The reaction was stirred at 0° for 1 hour, allowed to warm up to room temperature, stirred for 2 hours, and extracted with ethyl acetate (2×200 mL). The combined extracts were treated with 50 mL of 10% HCl (aqueous). The aqueous layer was washed with ethyl acetate, basified with K2CO3 and extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO4 and concentrated in vacuo to give 7.89 g of methyl 4-Boc-piperazine-2-acetate; 1H NMR (CDCl3) δ1.4 (s, 9), 2.31 (dd, 1), 2.37 (dd, 1), 2.55 (b, 1), 2.69-3.02 (m, 4), 3.75 (s, 3), 3.88 (b, 2).

Provenance & Evidence