Methanol → Methyl p-aminosalicylate

HRID 2107018Notes

Reaction equation

HRID 2107018 reaction equation
[OH:1][C:2]1[CH:10]=[C:9]([NH2:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.[CH3:17]O>>[OH:1][C:2]1[CH:10]=[C:9]([NH2:11])[CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:17])=[O:5]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 46494-Aminosalicylic Acid

Product 1

HCID 77787Methyl p-aminosalicylateYield 62%

Procedure

2-Hydroxy-4-aminobenzoic acid (100 g, 0.654 mole) was suspended in freshly distilled methanol (1 1), concentrated sulphuric acid (50 ml) was slowly added and the reaction mixture refluxed under nitrogen until all the material was dissolved (24-48 hours), after which it was concentrated to about 350 ml by evaporation, in vacuo. The concentrate was neutralized with 33% sodium hydroxide and 1M sodium hydrogen carbonate and extracted with ether (3×250 ml), the ether layer was washed with 1M sodium hydrogen carbonate (2×50 ml) and water (2×50 ml), dried over anhydrous magnesium sulphate (20 g), and the ether removed by evaporation, in vacuo. The product was dried, in vacuo, to give the title compound (67.5 g, 62%), m.p. 120°-122° C. Found (Calc. for C8H9NO3) C 57.57 (57.48), H 5.41 (5.39), N 8.22 (8.38).

Workup

  1. additionwas slowly added
  2. temperaturethe reaction mixture refluxed under nitrogen until all the material
  3. dissolutionwas dissolved (24-48 hours)
  4. concentrationafter which it was concentrated to about 350 ml by evaporation, in vacuo
  5. extractionextracted with ether (3×250 ml)
  6. washthe ether layer was washed with 1M sodium hydrogen carbonate (2×50 ml) and water (2×50 ml)
  7. dry with materialdried over anhydrous magnesium sulphate (20 g)
  8. customthe ether removed by evaporation, in vacuo
  9. customThe product was dried, in vacuo

Sources & evidence

ORD record
ord-9cd43d371f26461cbab9f768ba965588
Source dataset
uspto-grants-1990_06
Patent number
US04933330

Reaction notes

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