Dichloromethane → Benzyl 4-propionylpiperazine-1-carboxylate

Participants

Reaction Steps

A solution of benzyl piperazine-1-carboxylate (16, 10.0 g, 45.4 mmol), triethylamine (6.89 g, 68.0 mmol) and dry CH2Cl2 (150 mL) was cooled to 0° C. and propionyl chloride (4.62 g, 50.0 mmol) was added dropwise over 10 min. The reaction was kept under nitrogen and allowed to warm to room temperature. After stirring at rt for 17 h, water (50 mL) was added and the aqueous layer was extracted with CH2Cl2 (2×50 mL). The solution was dried over Na2SO4, filtered and concentrated to a yellow oil. The product was purified by silica gel chromatography eluting with 0-3% CH3OH in CH2Cl2 to afford the title compound (9.08 g, 72%) as a clear, colorless oil: 1H NMR (500 MHz, CDCl3) δ 7.40-7.30 (m, 5H), 5.15 (s, 2H), 3.70-3.35 (m, 8H), 2.35 (q, J=7.5 Hz, 2H), 1.15 (t, J=7.5 Hz, 3H).

Provenance & Evidence