Bromide ion → tert-Butyl 4-(prop-2-yn-1-yl)piperazine-1-carboxylate

HRID 1349978Notes

Reaction equation

HRID 1349978 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+].[Br-]>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

7

Reactant 4

HCID 259Bromide ionHCID 7842Propargyl bromideHCID 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 propargy 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-e275c4d8437945a79f26b413c84d292e
Source dataset
uspto-grants-2007_05
Patent number
US07214665B2

Reaction notes

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