Benzyl Bromide → Tert-butyl 4-benzyl-3-oxopiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution solution of Intermediate 1 (1.5 g, 7.5 mmol) in DMF (30 mL) at 0° C., under nitrogen, was added sodium hydride (330 mg of a 60% dispersion in mineral oil. 8.3 mmol). The solution was stirred for 90 min before benzyl bromide (1.16 mL, 9.8 mmol) was added. The solution was heated at 60° C. for 3 h then the solvent was removed in vacuo. The residue was partitioned between EtOAc (2×50 mL) and water (50 mL). The combined organic phases were dried (Na2SO4) and evaporated. The residue was chromatographed on silica, eluting with petrol:EtOAc (1:1), to afford the title amide (2.11 g, 97%) as a colourless solid. m.p. 85-88° C., 1H NMR (250 MHz, CDCl3) δ 1.46 (9H, s), 3.23-3.28 (2H, m), 3.56-3.61 (2H, m), 4.16 (2H, s), 4.63 (2H, s), 7.24-7.35 (5H, m).

Provenance & Evidence