Water → tert-Butyl 4-(4-amino-2-cyanophenyl)piperazine-1-carboxylate

HRID 1744508Notes

Reaction equation

HRID 1744508 reaction equation
[Cl-].[NH4+].O.[N+:4]([C:7]1[CH:8]=[CH:9][C:10]([N:15]2[CH2:20][CH2:19][N:18]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:17][CH2:16]2)=[C:11]([CH:14]=1)[C:12]#[N:13])([O-])=O>[Fe].C(O)C>[NH2:4][C:7]1[CH:8]=[CH:9][C:10]([N:15]2[CH2:16][CH2:17][N:18]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:19][CH2:20]2)=[C:11]([CH:14]=1)[C:12]#[N:13]

Participants

6

Reactant 3

HCID 962WaterHCID 25517Ammonium ChlorideHCID 22227995tert-Butyl 4-(2-cyano-4-nitrophenyl)piperazine-1-carboxylate

Product 1

HCID 22227872tert-Butyl 4-(4-amino-2-cyanophenyl)piperazine-1-carboxylateYield 89.7%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 702EthanolSolvent

Conditions

Temperature
65 °C

Procedure

Ammonium chloride (7.0 g) and iron powder (36.6 g) were added to a mixed solvent of water (180 ml) and ethanol (540 ml), and the mixture was heated to 65° C. Then, 5-nitro-2-(4-tert-butoxycarbonylpiperazin-1-yl)benzonitrile (62.1 g) was added in parts over 40 min and the mixture was stirred at a refluxing temperature for 1 h. The reaction mixture was ice-cooled and filtrated. The solvent was evaporated under reduced pressure. To the residue was added aqueous sodium hydroxide solution, and the mixture was extracted with toluene. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate, after which the solvent was evaporated under reduced pressure. Diisopropyl ether was added to the residue to allow crystallization. The crystals were recrystallized from a mixed solvent of ethyl acetate-n-hexane to give the title compound (50.7 g), melting point: 145° C.

Workup

  1. temperaturecooled
  2. filtrationfiltrated
  3. customThe solvent was evaporated under reduced pressure
  4. additionTo the residue was added aqueous sodium hydroxide solution
  5. extractionthe mixture was extracted with toluene
  6. washThe organic layer was washed with saturated brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. customafter which the solvent was evaporated under reduced pressure
  9. additionDiisopropyl ether was added to the residue
  10. customcrystallization
  11. customThe crystals were recrystallized from a mixed solvent of ethyl acetate-n-hexane

Sources & evidence

ORD record
ord-3bb855dadd7648d59566f59c27b57ee1
Source dataset
uspto-grants-2006_03
Patent number
US07015218B1

Reaction notes

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