Carbon Dioxide → 2-(3-(3-Methoxyphenyl)-1,2,4-oxadiazol-5-yl)pyridine

HRID 431897Notes

Reaction equation

HRID 431897 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7]([OH:9])=O.C(N1C=CN=C1)(N1C=CN=C1)=O.C(=O)=O.[CH3:25][O:26][C:27]1[CH:28]=[C:29]([CH:34]=[CH:35][CH:36]=1)[C:30](=[N:32]O)[NH2:31]>N1C=CC=CC=1>[CH3:25][O:26][C:27]1[CH:28]=[C:29]([C:30]2[N:31]=[C:7]([C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][N:1]=3)[O:9][N:32]=2)[CH:34]=[CH:35][CH:36]=1

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 1018Picolinic acidHCID 682631,1'-CarbonyldiimidazoleHCID 4192176N-Hydroxy-3-methoxy-benzamidine

Product 1

HCID 8514402-(3-(3-Methoxyphenyl)-1,2,4-oxadiazol-5-yl)pyridineYield 32%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

Using modifications of the method of Shine et al., J. Heterocyclic Chem. (1989) 26:125-128, a solution of picolinic acid (123 mg, 1 mmol) in pyridine (1 mL) was treated with 1,1′-carbonyldiimidazole (162 mg, 1 mmol) and the reaction stirred at ambient temperature until the evolution of carbon dioxide ceased (30 min). The intermediate acylimidazole was then treated with 3-methoxybenzamidoxime (166 mg, 1 mmol) and the reaction heated at reflux for 1 hour. Ice cold water was added to the reaction mixture to precipitate the oxadiazole. The solid was collected by filtration, washed with water and dried to afford 80 mg (32%) of 3-(3-methoxyphenyl)-5-(2-pyridyl)-1,2,4-oxadiazole: mp 90-94° C.; GC/EI-MS gave m/z (rel. int.) 253 (M+, 100), 254 (17), 179 (2), 175 (2), 149 (77), 133 (33), 119 (4), 106 (29), 78 (45), 51 (18).

Workup

  1. custom(30 min)
  2. temperaturethe reaction heated
  3. temperatureat reflux for 1 hour
  4. additionIce cold water was added to the reaction mixture
  5. customto precipitate the oxadiazole
  6. filtrationThe solid was collected by filtration
  7. washwashed with water
  8. customdried

Sources & evidence

ORD record
ord-1279d75e24494c7e9ab18a5b3a2a013e
Source dataset
uspto-grants-2003_12
Patent number
US06660753B2

Reaction notes

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