Sodium Hydroxide → Tert-butyl 4-[4-(4-amino-1,2,5-oxadiazol-3-yl)phenyl]piperazine-1-carboxylate

HRID 1744121Notes

Reaction equation

HRID 1744121 reaction equation
[C:1](/[C:3](=[N:23]\[OH:24])/[C:4]1[CH:9]=[CH:8][C:7]([N:10]2[CH2:15][CH2:14][N:13]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:12][CH2:11]2)=[CH:6][CH:5]=1)#[N:2].Cl.[NH2:26]O.C([O-])(O)=O.[Na+].[OH-].[Na+]>CCO.O.[Cl-].[Na+].O>[NH2:2][C:1]1[C:3]([C:4]2[CH:5]=[CH:6][C:7]([N:10]3[CH2:11][CH2:12][N:13]([C:16]([O:18][C:19]([CH3:20])([CH3:21])[CH3:22])=[O:17])[CH2:14][CH2:15]3)=[CH:8][CH:9]=2)=[N:23][O:24][N:26]=1

Participants

8

Reactant 4

HCID 14798Sodium Hydroxide2×HCID 443297Hydroxyamine hydrochloride2×HCID 516892Sodium Bicarbonate2×HCID 22236172tert-butyl 4-[4-[(Z)-C-cyano-N-hydroxycarbonimidoyl]phenyl]piperazine-1-carboxylate

Product 1

HCID 22235822Tert-butyl 4-[4-(4-amino-1,2,5-oxadiazol-3-yl)phenyl]piperazine-1-carboxylate

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolvent2×HCID 57417360Sodium chloride; waterSolvent

Procedure

To tert-butyl 4-{4-[(Z)-cyano(hydroxyimino)methyl]phenyl}piperazine-1-carboxylate (1.39 g, 4.21 mmol) in EtOH (50 mL) was added an aqueous solution of pre-mixed hydroxylamine hydrochloride (440 mg, 6.32 mmol) and NaHCO3 (535 mg, 6.32 mmol) in water (15 mL) and the reaction was refluxed overnight. An additional aliquot of hydroxylamine hydrochloride (440 mg, 6.32 mmol) and NaHCO3 (535 mg, 6.32 mmol) in water (10 mL) was added and the reaction was refluxed for 2 hours. Aqueous NaOH (1.0 M, 42.1 mL) was added and the reaction was refluxed for 1 hour. An additional aliquot of NaOH (1.0 M, 21 mL) was added and the reaction was refluxed for 3 hours. After cooling to rt, the reaction mixture was poured into brine and the product extracted with EtOAc (2×), dried over Na2SO4, concentrated in vacuo, and purified by flash chromatography over silica gel (EtOAc/Hex, 4/6) to afford tert-butyl 4-[4-(4-amino-1,2,5-oxadiazol-3-yl)phenyl]piperazine-1-carboxylate.

Workup

  1. temperaturethe reaction was refluxed overnight
  2. temperaturethe reaction was refluxed for 2 hours
  3. temperaturethe reaction was refluxed for 1 hour
  4. temperaturethe reaction was refluxed for 3 hours
  5. extractionthe product extracted with EtOAc (2×)
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated in vacuo
  8. custompurified by flash chromatography over silica gel (EtOAc/Hex, 4/6)

Sources & evidence

ORD record
ord-e7db718def9e4c408bcf41be36ee34f1
Source dataset
uspto-grants-2006_03
Patent number
US07012075B2

Reaction notes

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