Formic Acid → 1,3-Benzoxazole-6-carboxylic acid

HRID 2187359Notes

Reaction equation

HRID 2187359 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[OH:11].[CH:12](O)=O>>[O:11]1[C:3]2[CH:4]=[C:5]([C:6]([OH:8])=[O:7])[CH:9]=[CH:10][C:2]=2[N:1]=[CH:12]1

Participants

3

Reactant 2

HCID 284Formic AcidHCID 1375664-Amino-3-hydroxybenzoic acid

Product 1

HCID 222459381,3-Benzoxazole-6-carboxylic acid

Procedure

4-Amino-3-hydroxybenzoic acid (2.200 g) and formic acid (20 ml) were heated at 117° C. for 4 h. The reaction mixture was cooled to ambient temperature and the precipitated solid collected by filtration, washed with diethyl ether and dried at reduced pressure. The solid (0.580 g) was heated at reflux with zinc chloride (2.00 g) and c.H2SO4 (2 drops) in xylene (150 ml) under a Dean and Stark for 16 h. On cooling, water was added and the brown solid collected by filtration and washed with water. The resulting solid was washed with methanol and the solvent removed from the filtrate under reduced pressure to give the title compound as a dark brown solid (0.349 g).

Workup

  1. filtrationthe precipitated solid collected by filtration
  2. washwashed with diethyl ether
  3. customdried at reduced pressure
  4. temperatureThe solid (0.580 g) was heated
  5. temperatureat reflux with zinc chloride (2.00 g) and c
  6. temperatureOn cooling
  7. additionwater was added
  8. filtrationthe brown solid collected by filtration
  9. washwashed with water
  10. washThe resulting solid was washed with methanol
  11. customthe solvent removed from the filtrate under reduced pressure

Sources & evidence

ORD record
ord-95b04acef9cc4d68b7836c45da320fcb
Source dataset
uspto-grants-2002_06
Patent number
US06410529B1

Reaction notes

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