2-Aminophenol → 4-benzooxazol-2-ylbenzoic Acid

HRID 1068548Notes

Reaction equation

HRID 1068548 reaction equation
[C:1]([C:4]1[CH:11]=[CH:10][C:7]([CH:8]=[O:9])=[CH:6][CH:5]=1)([OH:3])=[O:2].[NH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1O.C(C(C#N)=C(C#N)C#N)#N>CC(N(C)C)=O>[C:1]([C:4]1[CH:11]=[CH:10][C:7]([C:8]2[O:9][C:14]3[CH:15]=[CH:16][CH:17]=[CH:18][C:13]=3[N:12]=2)=[CH:6][CH:5]=1)([OH:3])=[O:2]

Participants

5

Reactant 3

HCID 58012-AminophenolHCID 120884-Formylbenzoic acidHCID 12635Tetracyanoethylene

Product 1

HCID 98995224-benzooxazol-2-ylbenzoic Acid

Reagents, catalysts & solvents 1

HCID 31374DimethylacetamideSolvent

Procedure

Resin-bound 4-carboxybenzaldehyde (subn. 0.60 mmol/g, 400 mg, 0.24 mmol) was treated with a solution of 2-aminophenol (262 mg, 2.4 mmol) in DMA (3 mL). The suspension was shaken at room temperature for 24 h. Tetracyanoethylene (307 mg, 2.4 mmol) was added, and the mixture stirred at room temperature for an additional 24 h. The resin was filtered, washed with DMA and DCM, and dried under high vacuum. The benzoxazole was cleaved from the solid support with 20% (v/v) TFA in DCM (2×5 mL, 15 min) and the combined filtrates were evaporated to give the title compound. 1H NMR (CD3OD) δ 7.36-7.45 (m, 2H), 7.62-7,67 (m, 111), 7.72-7.77 (m, 1H), 8.17 (d, 2H, J=8.3 Hz), 8.29 (d, 2H, J=8.3 Hz). MS (API-ES+) m/z 240 (M+H).

Workup

  1. stirringthe mixture stirred at room temperature for an additional 24 h
  2. filtrationThe resin was filtered
  3. washwashed with DMA and DCM
  4. customdried under high vacuum
  5. customwas cleaved from the solid support with 20% (v/v) TFA in DCM (2×5 mL, 15 min)
  6. customthe combined filtrates were evaporated

Sources & evidence

ORD record
ord-65f81da995be46f8b80f81d09e79ce99
Source dataset
uspto-grants-2001_06
Patent number
US06251689B1

Reaction notes

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