Sulfuric Acid → 1,2-Benzoxazole-3-carboxylic acid

HRID 1721814Notes

Reaction equation

HRID 1721814 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[C:3]([C:10]([O:12]CC)=[O:11])=[N:2]1.S(=O)(=O)(O)O>O>[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[C:3]([C:10]([OH:12])=[O:11])=[N:2]1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 14177940Ethyl 1,2-benzoxazole-3-carboxylate

Product 1

HCID 27354451,2-Benzoxazole-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
80 °C

Procedure

8.6 g of 3B was mixed with 175 ml of 70% sulfuric acid and the mixture was heated at 80° C. for 4 hours. The mixture was cooled, 200 ml of cold water was added, the mixture was extracted with ether, and the extract was dried (Na2SO4) and stripped of solvent. The residue was triturated with pentane, and the solid was collected and dried to give 3-benzisoxazolecarboxylic acid (3C), as a white solid, m.p.: 132°-134° C. (with decomposition).

Workup

  1. temperatureThe mixture was cooled
  2. extractionthe mixture was extracted with ether
  3. dry with materialthe extract was dried (Na2SO4)
  4. customThe residue was triturated with pentane
  5. customthe solid was collected
  6. customdried

Sources & evidence

ORD record
ord-5be5687c9cf8431cb49bf698e77ca31b
Source dataset
uspto-grants-1989_08
Patent number
US04853027

Reaction notes

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