Propargyl bromide → tert-Butyl 4-(prop-2-yn-1-yl)piperazine-1-carboxylate

HRID 2242897Notes

Reaction equation

HRID 2242897 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C([O-])([O-])=O.[K+].[K+].[CH2:20](Br)[C:21]#[CH:22]>>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([CH2:22][C:21]#[CH:20])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 3

HCID 7842Propargyl bromideHCID 11430Potassium CarbonateHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 11287538tert-Butyl 4-(prop-2-yn-1-yl)piperazine-1-carboxylate

Procedure

To a vigorously stirred suspension of piperazine-1-carboxylic acid tert-butyl ester (4.2 g, 22.5 mmol) and K2CO3 (1.2 eq, 27 mmol, 3.7 g) was added propargyl bromide (80 wt % in toluene, 1.2 eq, 27 mmol) dropwise via syringe over 20 minutes. The mixture was stirred at room temperature overnight (about 20 hours), concentrated in vacuo and partitioned between water and EtOAc. The organic-phase was washed twice with water, dried over MgSO4, filtered and evaporated to afford a clear yellow oil that partially solidified upon prolonged standing and was used directly without further purification. 1H NMR (400 MHz, CDCl3) d 1.47 (s, 9H), 2.28 (t, 1H), 2.54 (m, 4H), 3.34 (d, 2H, J=2.4 Hz), 3.49 (m, 4H). MS: m/z 225 (M+1).

Workup

  1. concentrationconcentrated in vacuo
  2. custompartitioned between water and EtOAc
  3. washThe organic-phase was washed twice with water
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. customevaporated
  7. customto afford a clear yellow oil
  8. customwas used directly without further purification

Sources & evidence

ORD record
ord-2c2d67fe34044d68a1a885c3e48381a2
Source dataset
uspto-grants-2010_03
Patent number
US07674791B2

Reaction notes

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