Triethylamine → Ethyl 3-oxopiperazine-1-carboxylate

Participants

Reaction Steps

To a solution of 2-piperazinone (5.0 g, 50.0 mmol) and triethylamine (11.09 g, 110.0 mmol) in DCM (15 mL) is added ethyl chloroformate (5.9 g, 55.0 mmol) at room temperature and the reaction mixture is stirred for 2 h. The reaction is quenched with water (100 mL) and extracted with DCM (3×100 mL). The combined organic layers are dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The residue is triturated with Et2O to give the title compound (5.0 g, 29.05 mmol) as a pale yellow solid. 1H-NMR (400 MHz, DMSO-d6): δ 1.19 (t, 3H), 3.16-3.19 (m, 2H), 3.48-3.51 (m, 2H), 3.85 (s, 2H), 4.05 (q, 2H), 8.06 (s, 1H).

Provenance & Evidence