Sulfuric Acid → Methyl 5-amino-2-hydroxybenzoate

HRID 66223

Reaction equation

HRID 66223 reaction equation
[NH2:1][C:2]1[CH:10]=[C:6]([C:7]([OH:9])=[O:8])[C:5]([OH:11])=[CH:4][CH:3]=1.S(=O)(=O)(O)O.[C:17](=O)([O-])[O-].[Na+].[Na+]>CO>[CH3:17][O:8][C:7](=[O:9])[C:6]1[C:5](=[CH:4][CH:3]=[C:2]([NH2:1])[CH:10]=1)[OH:11]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 40755-Aminosalicylic AcidHCID 10340Sodium Carbonate

Product 1

HCID 135127Methyl 5-amino-2-hydroxybenzoate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 20.0 g of 5-aminosalicylic acid, 250 ml of methanol and 10 ml of concentrated sulfuric acid is refluxed overnight. The reaction mixture is cooled, made alkaline with dilute aqueous sodium carbonate solution and concentrated. The resulting solid is separated and washed with water. The solid is then washed with ether, and the ether is evaporated to dryness yielding a brown solid. The aqueous filtrate above is extracted with ether, the extract is dried over anhydrous sodium sulfate, and evaporated yielding a brown solid. The solids are combined and recrystallized from ether to afford 10.7 g of 5-aminosalicylic acid methyl ester.

Workup

  1. temperatureThe reaction mixture is cooled
  2. concentrationconcentrated
  3. customThe resulting solid is separated
  4. washwashed with water
  5. washThe solid is then washed with ether
  6. customthe ether is evaporated to dryness
  7. customyielding a brown solid
  8. extractionThe aqueous filtrate above is extracted with ether
  9. dry with materialthe extract is dried over anhydrous sodium sulfate
  10. customevaporated
  11. customyielding a brown solid
  12. customrecrystallized from ether

Sources & evidence

ORD record
ord-b81ed494e9ea4bc4968e388da24bf6d5
Source dataset
uspto-grants-1978_12
Patent number
US04130660

Linked notes

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