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

HRID 1668291Notes

Reaction equation

HRID 1668291 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].[CH2:14](Br)[C:15]#[CH:16].C(=O)([O-])[O-].[K+].[K+]>C(#N)C.ClCCl>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([CH2:16][C:15]#[CH:14])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

6

Reactant 3

HCID 7842Propargyl bromide2×HCID 11430Potassium CarbonateHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 11287538tert-Butyl 4-(prop-2-yn-1-yl)piperazine-1-carboxylateYield 46%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of 10.0 g (54.8 mmol) of tert-butyl-1-piperazine carboxylate in 60 mL acetonitile was added 5.20 mL (60.4 mmol) propargyl bromide and 37.9 g (274 mmol) anhydrous potassium carbonate. Additional propargyl bromide, 1.5 mL, was added after stirring for 36 hours at room temperature. The residue was evaporated to dryness. Dichloromethane, 50 mL, and water, 50 mL, were added. The reaction mixture was extracted with CH2Cl2, 4×40 mL, dried over magnesium sulfate, and evaporate to provide a brown oil. The oil was dissolved in dichloromethane and purify with a RT Scientific system using hexane/ethyl acetate gradient to yield 5.5 g (46%) of yellow oil, which ultimately crystallized upon standing.

Workup

  1. customThe residue was evaporated to dryness
  2. additionDichloromethane, 50 mL, and water, 50 mL, were added
  3. extractionThe reaction mixture was extracted with CH2Cl2, 4×40 mL
  4. dry with materialdried over magnesium sulfate
  5. customevaporate
  6. customto provide a brown oil
  7. custompurify with a RT Scientific system

Sources & evidence

ORD record
ord-fc93313ee4ed4c0e85b286462542df1b
Source dataset
uspto-grants-2011_08
Patent number
US07989431B2

Reaction notes

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