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

HRID 1641807Notes

Reaction equation

HRID 1641807 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][C:17]([N+:20]([O-])=O)=[CH:16][C:15]=2[C:23]#[N:24])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Cl-].[NH4+]>CO.[Zn]>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][C:17]([NH2:20])=[CH:16][C:15]=2[C:23]#[N:24])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

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

Product 1

HCID 22227872tert-Butyl 4-(4-amino-2-cyanophenyl)piperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 887MethanolSolvent

Procedure

4-(2-Cyano-4-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (587 mg, 1.77 mmol) was dissolved in methanol (50 mL) and to this solution was added ammonium chloride (945 mg, 17.66 mmol) and zinc (1155 mg, 17.66 mmol). The mixture was magnetically stirred for 3 hr and the mixture was filtered through a pad of celite. The solids were rinsed with methanol and the combined filtrate was concentrated to a yellow solid. This crude intermediate was dissolved in ethyl acetate (400 mL) and the resulting solution was washed with water (400 mL) and brine (200 mL). The organic layer was collected, dried over sodium sulfate, and concentrated to give 4-(4-amino-2-cyano-phenyl)-piperazine-1-carboxylic acid tert-butyl ester that was used in the next step without further purification.

Workup

  1. filtrationthe mixture was filtered through a pad of celite
  2. washThe solids were rinsed with methanol
  3. concentrationthe combined filtrate was concentrated to a yellow solid
  4. dissolutionThis crude intermediate was dissolved in ethyl acetate (400 mL)
  5. washthe resulting solution was washed with water (400 mL) and brine (200 mL)
  6. customThe organic layer was collected
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-25fae18e38ab4b2eaf7cb11df7517297
Source dataset
uspto-grants-2012_02
Patent number
US08115011B2

Reaction notes

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