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

To 1-methylpiperazine (37.7 ml, 337 mmol) and K2CO3 (46.6 g, 337 mmol) in acetone (380 ml) was added propargyl bromide (25 ml, 225 mmol, 80% in toluene) in acetone (70 ml) dropwise at 0° C. under N2. The internal temperature of the reaction was kept <10° C. The reaction was stirred at room temperature for 3 hours. The reaction was filtered, and the salts were washed with small portions of acetone (×2). The filtrates were combined evaporated to concentration (gently). To the residue was added water and the product was extracted with DCM (×3). The combined organic layers were washed with brine and dried over MgSO4. The product was filtered and evaporated to dryness to yield 1-methyl-4-prop-2-ynyl-piperazine as a yellow oil.

1. customwas kept <10° C
2. filtrationThe reaction was filtered
3. washthe salts were washed with small portions of acetone (×2)
4. customThe filtrates were combined evaporated to concentration (gently)
5. additionTo the residue was added water
6. extractionthe product was extracted with DCM (×3)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over MgSO4
9. filtrationThe product was filtered
10. customevaporated to dryness

ORD record

ord-445548358d9d4354b87c7e482d4c1d64

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08916552B2