Cyanogen Bromide → tert-Butyl 4-cyanopiperazine-1-carboxylate

HRID 1775318Notes

Reaction equation

HRID 1775318 reaction equation
[N:1]1([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.[CH:14]([N:17](CC)C(C)C)(C)C.N#CBr>ClCCl.O>[C:14]([N:4]1[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]1)#[N:17]

Participants

6

Reactant 3

HCID 10476Cyanogen BromideHCID 81531DiisopropylethylamineHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 14068968tert-Butyl 4-cyanopiperazine-1-carboxylateYield 72.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled (0° C.) solution of tert-butyl piperazine-1-carboxylate (1.517 g, 8.14 mmol) in dichloromethane (10 mL) were added N,N-diisopropylethylamine (1.54 mL, 9.00 mmol) and cyanogen bromide (911 mg, 8.60 mmol) and the reaction was stirred for 45 min at 0° C. The reaction mixture was warmed to room temperature, poured in water (100 mL) and extracted with EtOAc (100 mL). The organic layer was washed with water and brine, dried (Na2SO4) and concentrated under reduced pressure. The residue was washed twice with heptane and dried in vacuo, yielding 1.24 g (5.87 mmol, 72%) of a white solid that was used directly in the next step.

Workup

  1. temperatureThe reaction mixture was warmed to room temperature
  2. extractionextracted with EtOAc (100 mL)
  3. washThe organic layer was washed with water and brine
  4. dry with materialdried (Na2SO4)
  5. concentrationconcentrated under reduced pressure
  6. washThe residue was washed twice with heptane
  7. customdried in vacuo

Sources & evidence

ORD record
ord-10d2bbb675e84fa2b7f4c0f56f6b89ca
Source dataset
uspto-grants-2016_02
Patent number
US09260441B2

Reaction notes

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