Acetic Anhydride → 3-Methylbenzo[d]isoxazole

HRID 1293101Notes

Reaction equation

HRID 1293101 reaction equation
C(OC(=O)C)(=O)C.O[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[C:15](=[N:17][OH:18])[CH3:16].C(=O)([O-])[O-].[K+].[K+].C(OCC)(=O)C>CN(C=O)C.O>[CH3:16][C:15]1[C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=2[O:18][N:17]=1

Participants

7

Reactant 4

HCID 7918Acetic AnhydrideHCID 8857Ethyl AcetateHCID 11430Potassium CarbonateHCID 1020211-(2-Hydroxyphenyl)ethanone oxime

Product 1

HCID 40681043-Methylbenzo[d]isoxazoleYield 84.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

Acetic anhydride (7.1 mL, 75 mmol) was added to 24 (7.55 g, 50 mmol) in a 100 mL flask. The mixture was heated to 60° C. for 3 hours followed by evaporation to dryness. Potassium carbonate (8.7 g, 63 mmol) was partly dissolved in 40 mL DMF and added to the mixture. The mixture was stirred at room temperature overnight and finally heated to 100° C. for 30 minutes. Ethyl acetate and water were added. The phases were separated and the aqueous phase was extracted with ethyl acetate and dichloromethane. The combined organic phases were dried over magnesium sulphate and evaporated to dryness to give 5.6 g of a yellow oil. Crude product was purified by column chromatography (100% dichloromethane), producing pure 25 (4.6 g). 1H NMR (CDCl3) δ 2.6 (s, 3H), 7.3 (m, 1H), 7.55 (m, 2H), 7.65 (m, 1H).

Workup

  1. customfollowed by evaporation to dryness
  2. additionadded to the mixture
  3. temperaturefinally heated to 100° C. for 30 minutes
  4. customThe phases were separated
  5. extractionthe aqueous phase was extracted with ethyl acetate and dichloromethane
  6. dry with materialThe combined organic phases were dried over magnesium sulphate
  7. customevaporated to dryness

Sources & evidence

ORD record
ord-718e9bb5796244a7bece2c539c62b4b5
Source dataset
uspto-grants-2007_07
Patent number
US07238713B2

Reaction notes

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