Reaction #2446124

Reaction equation

Propargyl bromide

tert-butyl 1-piperazinecarboxylate

diisopropylethylamine

→

tert-butyl 4-propargylpiperazine-1-carboxylate

Solvents

CHCl3

CHCl3

Conditions

Workup

1. 1
   Washthe solution was washed with 5% NaHCO3 (3×50 ml), brine (2×50 ml)
2. 2
   Dryingdried over Na2SO4
3. 3
   FiltrationThe solution was filtered
4. 4
   Otherevaporated to dryness
5. 5
   OtherThe residue was crystallized from a mixture of benzene-hexane (1:1)

Procedure

Propargyl bromide (356.9 mg, 3 mmol) was slowly added to a mixture of tert-butyl 1-piperazinecarboxylate obtained in step 2(i) above (558.8 mg, 3 mmole) and diisopropylethylamine (407.1 mg, 3.15 mmol) in CHCl3 (25 ml) at 0° C. The mixture was stirred for 24 h at room temperature. 50 ml of CHCl3 was then added and the solution was washed with 5% NaHCO3 (3×50 ml), brine (2×50 ml), and then dried over Na2SO4. The solution was filtered and evaporated to dryness. The residue was crystallized from a mixture of benzene-hexane (1:1) to give tert-butyl 4-propargylpiperazine-1-carboxylate (D6) (crude 337 mg, 86%). H1 NMR (250 MHz, CDCl3): 1.42 (s, 9H), 2.22 (s, 1H), 2.46 (s, 4H), 3.26 (s, 2H), 3.41 (s, 4H).

Source