Ammonium formate → Methyl 2-amino-4-hydroxybenzoate

HRID 29689Notes

Reaction equation

HRID 29689 reaction equation
[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][C:5]=1[N+:11]([O-])=O.C([O-])=O.[NH4+]>CO.[Pd]>[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][C:5]=1[NH2:11]

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 21082409Methyl 4-hydroxy-2-nitrobenzoate

Product 1

HCID 20327956Methyl 2-amino-4-hydroxybenzoateYield 96.1%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

To a stirred solution of 4-hydroxy-2-nitrobenzoic acid methyl ester (4.410 g, 22.369 mmol) in methanol (80 ml) under nitrogen at room temperature was added ammonium formate (5.642 g, 89.475 mmol) and 5% Pd/C (450 mg). After 5 hours the reaction mixture was filtered through celite and rinsed. The filtrate was concentrated and the residue partitioned between EtOAc (150 ml) and water (40 ml). The layers were shaken, separated and the organic layer washed with water (3×30 ml), brine (2×30 ml), dried over Na2SO4, filtered, concentrated and dried to give 2-amino-4-hydroxy-benzoic acid methyl ester (3.593 g, 21.494 mmol, 96%) as an off-white solid, dec. 113-118° C. 1H NMR (DMSO-d6) δ 3.70 (s, 3H), 5.98 (dd, 1H), 6.10 (s, 1H), 6.59 (s, 1H), 7.54 (d, 1H), 9.81 (s, 1H); mass spectrum [ES(−)], m/z 166 (M−H)−.

Workup

  1. filtrationAfter 5 hours the reaction mixture was filtered through celite
  2. washrinsed
  3. concentrationThe filtrate was concentrated
  4. customthe residue partitioned between EtOAc (150 ml) and water (40 ml)
  5. customseparated
  6. washthe organic layer washed with water (3×30 ml), brine (2×30 ml)
  7. dry with materialdried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customdried

Sources & evidence

ORD record
ord-91d40f49a0f447af955b74f8cc603733
Source dataset
uspto-grants-2008_09
Patent number
US07420083B2

Reaction notes

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