4-Cyanophenol → 4,N-Dihydroxy-benzamidine

HRID 1821134Notes

Reaction equation

HRID 1821134 reaction equation
Cl.[NH2:2][OH:3].[OH:4][C:5]1[CH:12]=[CH:11][C:8]([C:9]#[N:10])=[CH:7][CH:6]=1>CO>[OH:4][C:5]1[CH:12]=[CH:11][C:8]([C:9]([NH:2][OH:3])=[NH:10])=[CH:7][CH:6]=1

Participants

4

Reactant 2

HCID 130194-CyanophenolHCID 443297Hydroxyamine hydrochloride

Product 1

HCID 51497564,N-Dihydroxy-benzamidineYield 69.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To dry methanol (285 mL) is carefully added K-tert.-butylate (28.28 g, 252 mmol) followed by hydroxylamine hydrochloride (15.0 g, 216 mmol). The suspension is stirred for 30 min before 4-hydroxybenzonitrile (8.58 g, 72 mmol) is added. The mixture is refluxed for 40 h, the solvent is evaporated and the residue is acidified by adding 2 N aq. HCl. The solution is extracted twice with DCM (100 mL). The aq. layer is basified by adding solid NaHCO3. The product precipitates, is filtered off, washed with water and dried to give 4,N-dihydroxy-benzamidine (7.6 g) as a brownish solid; 1H NMR (D6-DMSO): δ 9.57 (s, 1H), 9.33 (s, 1H), 7.48-7.42 (m, 2H), 6.74-6.68 (m, 2H), 5.62 (s, 2H).

Workup

  1. additionis added
  2. temperatureThe mixture is refluxed for 40 h
  3. customthe solvent is evaporated
  4. additionby adding 2 N aq. HCl
  5. extractionThe solution is extracted twice with DCM (100 mL)
  6. additionby adding solid NaHCO3
  7. customThe product precipitates
  8. filtrationis filtered off
  9. washwashed with water
  10. customdried

Sources & evidence

ORD record
ord-7212708e57114eb28bc8060cbeeafcac
Source dataset
uspto-grants-2009_10
Patent number
US07605269B2

Reaction notes

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