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

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).

1. temperatureTo a stirred, chilled
2. filtrationfiltered
3. concentrationthe filtrate was concentrated in vacuo
4. concentrationThe filtrate was concentrated to an orange oil (8.2 g)
5. distillationThe product was distilled under high vacuum
6. distillationThe product distilled between 95-120° C. head temperature

ORD record

ord-630eedc588774057993fe07bc78ab875

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07723330B2