Ethanol → 5-(2-Bromophenyl)-3-methyl-1,2,4-oxadiazole

HRID 478240Notes

Reaction equation

HRID 478240 reaction equation
C(O)C.[Na].[C:5](=[N:8][OH:9])([NH2:7])[CH3:6].[Br:10][C:11]1[CH:20]=[CH:19][CH:18]=[CH:17][C:12]=1[C:13](OC)=O>O>[Br:10][C:11]1[CH:20]=[CH:19][CH:18]=[CH:17][C:12]=1[C:13]1[O:9][N:8]=[C:5]([CH3:6])[N:7]=1

Participants

6

Reactant 4

HCID 702EthanolHCID 11894Methyl 2-bromobenzoateHCID 30926N-HydroxyacetamidineHCID 5360545Sodium

Product 1

HCID 180013105-(2-Bromophenyl)-3-methyl-1,2,4-oxadiazoleYield 33.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To activated molecular sieves (2.0 g, 4 Å powdered) was added ethanol (20 ml) followed by sodium metal (0.435 g, 18.9 mmol), and the mixture heated at reflux for 15 min. After cooling to ambient temperature, acetamide oxime (1.4 g, 18.9 mmol) was added and the suspension stirred for 15 min. Methyl 2-bromobenzoate (1.32 ml, 9.5 mmol) was added and the mixture heated at reflux for 2 h. The reaction was poured into water and extracted with ethyl acetate. The organic phase was separated, dried over magnesium sulfate, filtered and evaporated to give a white solid. The crude product was purified by crystallisation from ethyl acetatelisohexane to give 5-(2-bromophenyl)-3-methyl-[1,2,4]oxadiazole as a white solid (0.76 g): δH (400 MHz, CDCl3) 2.52 (3H, s), 7.45 (2H, m), 7.76 (1H, dd, J 7.8 and 1.2), 7.97 (1H, dd, J 7.8 and 1.2); m/z (ES+) 239:241 (1:1) (M++H).

Workup

  1. temperaturethe mixture heated
  2. temperatureat reflux for 15 min
  3. temperaturethe mixture heated
  4. temperatureat reflux for 2 h
  5. extractionextracted with ethyl acetate
  6. customThe organic phase was separated
  7. dry with materialdried over magnesium sulfate
  8. filtrationfiltered
  9. customevaporated
  10. customto give a white solid
  11. customThe crude product was purified by crystallisation from ethyl acetatelisohexane

Sources & evidence

ORD record
ord-d342ec1173e74ae9a8f686319544af81
Source dataset
uspto-grants-2003_11
Patent number
US06642229B2

Reaction notes

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