Ethyl Acetate → 5-[(E)-2-phenylethenyl]-1,2,4-oxadiazole

HRID 967754

Reaction equation

HRID 967754 reaction equation
O[NH:2][CH:3]=[N:4][C:5](=[O:14])[CH:6]=[CH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.C([O-])([O-])=O.[K+].[K+].C(OCC)(=O)C>C(O)(=O)C.O1CCOCC1>[C:8]1(/[CH:7]=[CH:6]/[C:5]2[O:14][N:2]=[CH:3][N:4]=2)[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 11430Potassium CarbonateHCID 178520452HCID 178520452, compound

Product 1

HCID 222913425-[(E)-2-phenylethenyl]-1,2,4-oxadiazoleYield 8%

Reagents, catalysts & solvents 1

HCID 22565020HOAc dioxaneSolvent

Procedure

N-[(Hydroxyamino)methylene]-cinnamamide (850 mg, 4.5 mmol) was dissolved in acetic acid/dioxane (20 mL 1:1 v:v), and heated to reflux for 2 h. The cooled solution was made basic (pH 8) with K2CO3, and partitioned between ethyl acetate and water. The organics were dried over Na2SO4, and concentrated in vacuo. The resultant solids were triturated with hot ethyl acetate, and the soluble portion was purified by flash column chromatography on silica eluting with 2:1 hexane:ethyl acetate to afford 5-[(E)-2-phenylethenyl]-1,2,4-oxadiazole (60 mg, 8% yield) as a white powder. M.p. 53–55° C. 1H NMR (CDCl3, 300 MHz) δ8.43 (s, 1H), 7.85 (d, J=16 Hz, 1H), 7.60 (m, 2H), 7.45 (m, 3H), 7.05 (d, J=16 Hz, 1H). MS (EI ionization) 171 (M+−H).

Workup

  1. temperatureheated
  2. temperatureto reflux for 2 h
  3. custompartitioned between ethyl acetate and water
  4. dry with materialThe organics were dried over Na2SO4
  5. concentrationconcentrated in vacuo
  6. customThe resultant solids were triturated with hot ethyl acetate
  7. customthe soluble portion was purified by flash column chromatography on silica eluting with 2:1 hexane

Sources & evidence

ORD record
ord-6ad1428dd2c64d83a156f20351cef2f1
Source dataset
uspto-grants-2005_10
Patent number
US06956049B1

Linked notes

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