4,6-dichloro-3-hydroxy-2-nitrobenzoic acid → HCID 86749538, compound

HRID 259932Notes

Reaction equation

HRID 259932 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([Cl:11])[C:5]([C:6]([OH:8])=[O:7])=[C:4]([N+:12]([O-])=O)[C:3]=1[OH:15]>CCO.[Pd]>[ClH:1].[Cl:1][C:2]1[C:3]([OH:15])=[C:4]([NH2:12])[C:5](=[C:9]([Cl:11])[CH:10]=1)[C:6]([OH:8])=[O:7]

Participants

4

Reactant 1

HCID 106584324,6-dichloro-3-hydroxy-2-nitrobenzoic acid

Product 1

HCID 86749538HCID 86749538, compoundYield 28.1%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

4,6-Dichloro-3-hydroxy-2-nitrobenzoic acid (223 mg, 0.88 mmol) was dissolved in EtOH (50 mL) and Pd/C (10%, 30 mg) was added. Hydrogenation at atmospheric pressure and at room temperature for 1 h, filtration and evaporation of the solvent gave 205 mg of crude product. Purification by column chromatography (SiO2, EtOAc-HOAc 50:1) gave a residue which was recrystallized from MeOH/water (0.5/1.5 mL). Column chromatography (SiO2, EtOAc-HOAc 400:1) followed by dissolving the free amine in THF (0.6 mL) and precipitating the hydrochloride by adding HCl/Et2O (3M, 1 mL) and Et2O (1 mL) gave 4,6-dichloro-3-hydroxyanthranilic acid hydrochloride (32 mg). Mp: 231° C. (dec.). 1H NMR (DMSO-d6): δ7.0 (br, 5H), 6.68 (s, 1H). 13C NMR (DMSO-d6): δ167.15, 140.27, 139.05, 122.49, 121.88, 116.24, 113.99. MS (EI, 70 eV): m/z (rel. int.) 223/221 (M+, 42/65).

Workup

  1. filtrationfiltration and evaporation of the solvent
  2. customgave 205 mg of crude product
  3. customPurification by column chromatography (SiO2, EtOAc-HOAc 50:1)
  4. customgave a residue which
  5. customwas recrystallized from MeOH/water (0.5/1.5 mL)
  6. dissolutionby dissolving the free amine in THF (0.6 mL)
  7. customprecipitating the hydrochloride
  8. additionby adding HCl/Et2O (3M, 1 mL) and Et2O (1 mL)

Sources & evidence

ORD record
ord-dd574f7b285742ac81acf1c0392d8587
Source dataset
uspto-grants-1996_06
Patent number
US05523475

Reaction notes

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