Propargyl bromide → 1-Methyl-4-(prop-2-yn-1-yl)piperazine

Participants

Reaction Steps

To a stirred, chilled suspension of 1-methylpiperazine (10.0 g, 100.0 mmol) and cesium carbonate (32.6 g, 100.0 mmol) in acetone (200 mL) was added 3-bromoprop-1-yne (11.0 mL, 100 mmol) (80% in toluene). The reaction was stirred for 18 hours at room temperature under N2. The suspension was diluted with diethyl ether (200 mL) and filtered, and the filtrate was concentrated in vacuo. The resulting residue was resuspended in diethyl ether (100 mL) and refiltered. The filtrate was concentrated to an orange oil (8.2 g). The product was distilled under high vacuum. The product distilled between 95-120° C. head temperature. The product was obtained as a colorless oil (5.46 g, 32%). 1H NMR (400 MHz, CDCl3) δ 3.31 (m, 2H), 2.89 (m, 1H), 2.3-2.6 (m, 8H), 2.30 (m, 3H).

Provenance & Evidence