Ethyl orthoformate → (E)-3-(4-chloro-3-trifluoromethyl-styryl)-1,2,4-oxadiazole

HRID 1491968Notes

Reaction equation

HRID 1491968 reaction equation
[Cl:1][C:2]1[CH:13]=[CH:12][C:5](/[CH:6]=[CH:7]/[C:8](=[N:10][OH:11])[NH2:9])=[CH:4][C:3]=1[C:14]([F:17])([F:16])[F:15].[CH:18](OCC)(OCC)OCC>B(F)(F)F.CCOCC>[Cl:1][C:2]1[CH:13]=[CH:12][C:5](/[CH:6]=[CH:7]/[C:8]2[N:9]=[CH:18][O:11][N:10]=2)=[CH:4][C:3]=1[C:14]([F:15])([F:16])[F:17]

Participants

4

Reactant 2

HCID 31214Ethyl orthoformateHCID 86748304(E)-4-chloro-3-trifluoromethyl-cinnamamide oxime

Product 1

HCID 23364566(E)-3-(4-chloro-3-trifluoromethyl-styryl)-1,2,4-oxadiazoleYield 71%

Reagents, catalysts & solvents 1

HCID 8000Boron trifluoride etherateCatalyst

Procedure

5.2 g (0.02 mol) of (E)-4-chloro-3-trifluoromethyl-cinnamamide oxime are introduced into 50 ml of triethyl orthoformate and 2 drops of boron trifluoride etherate are added at room temperature. The mixture is then stirred for 2 hours at reflux temperature and the entire batch is concentrated in vacuo. The residue is taken up in 100 ml of methylene chloride and washed in succession with 100 ml of 2N hydrochloric acid, saturated sodium carbonate solution and water. The organic phase is dried over sodium sulphate and the solvent is subsequently distilled off. 3.9 g (71.0% of theory) of (E)-3-(4-chloro-3-trifluoromethyl-styryl)-1,2,4-oxadiazole are obtained.

Workup

  1. additionare added at room temperature
  2. temperatureat reflux temperature
  3. concentrationthe entire batch is concentrated in vacuo
  4. washwashed in succession with 100 ml of 2N hydrochloric acid, saturated sodium carbonate solution and water
  5. dry with materialThe organic phase is dried over sodium sulphate
  6. distillationthe solvent is subsequently distilled off

Sources & evidence

ORD record
ord-26b40f4176154b0597afba6c376cc1e9
Source dataset
uspto-grants-1994_12
Patent number
US05371231

Reaction notes

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