Phosphorus oxychloride → 1,3,4-Oxadiazole, 2-methyl-5-(2-thienyl)-

HRID 2296668Notes

Reaction equation

HRID 2296668 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([NH:8][NH:9][C:10](=[O:12])[CH3:11])=O.P(Cl)(Cl)(Cl)=O>>[CH3:11][C:10]1[O:12][C:6]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)=[N:8][N:9]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 960022HCID 960022, compound

Product 1

HCID 102614421,3,4-Oxadiazole, 2-methyl-5-(2-thienyl)-Yield 75.3%

Conditions

Temperature
90 °C

Procedure

A mixture of N-(2-thienylcarbonylamino)ethanamide (5.37 g) and phosphorus oxychloride (15 ml) was stirred for 8 hours at 90° C. After cooling to ambient temperature, the mixture was concentrated. The residue was partitioned between AcOEt and saturated aqueous NaHCO3 solution. The organic layer was separated and washed with saturated aqueous NaHCO3 solution and brine. The resulting solution was dried over sodium sulfate and concentrated to give 3.65 g of 2methyl-5-(2-thienyl)-1,3,4-oxadiazole as a solid.

Workup

  1. temperatureAfter cooling to ambient temperature
  2. concentrationthe mixture was concentrated
  3. customThe residue was partitioned between AcOEt and saturated aqueous NaHCO3 solution
  4. customThe organic layer was separated
  5. washwashed with saturated aqueous NaHCO3 solution and brine
  6. dry with materialThe resulting solution was dried over sodium sulfate
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-7ae2158dd88c48908f36899cd468df7f
Source dataset
uspto-grants-2002_12
Patent number
US06489324B2

Reaction notes

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