Triethylamine → 2-Fluoro-5-(trifluoromethoxy)benzonitrile

HRID 2113446Notes

Reaction equation

HRID 2113446 reaction equation
[F:1][C:2]1[CH:10]=[CH:9][C:8]([O:11][C:12]([F:15])([F:14])[F:13])=[CH:7][C:3]=1/[CH:4]=[N:5]/O.C(N(CC)CC)C.FC(F)(F)C(OC(=O)C(F)(F)F)=O>C1COCC1>[F:1][C:2]1[CH:10]=[CH:9][C:8]([O:11][C:12]([F:13])([F:14])[F:15])=[CH:7][C:3]=1[C:4]#[N:5]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 9845Trifluoroacetic anhydrideHCID 87441576(NE)-N-[[2-fluoro-5-(trifluoromethoxy)phenyl]methylidene]hydroxylamine

Product 1

HCID 52210952-Fluoro-5-(trifluoromethoxy)benzonitrileYield 83%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of E-2-fluoro-5-trifluoromethoxy-benzaldehyde oxime (47.5 g, 213 mmol) in THF (400 ml) was added triethylamine (65.0 ml, 466 mmol). The mixture was cooled in an ice bath and trifluoroacetic anhydride (32.8 ml, 236 mmol) was added at such a rate that the temperature was kept <30° C. After 1 h at rt all volatiles were evaporated (40° C., 200 mbar). The oily residue was partitioned (ether/water), the organic phase was dried (Na2SO4) and concentrated. Distillation (24 mbar, T=80-83° C.) afforded the title compound (36.1 g, 83%) that was sufficiently pure to be used in the next step. MS: m/e=205 [M]+.

Workup

  1. temperatureThe mixture was cooled in an ice bath
  2. customwas kept <30° C
  3. customAfter 1 h at rt all volatiles were evaporated (40° C., 200 mbar)
  4. customThe oily residue was partitioned (ether/water)
  5. dry with materialthe organic phase was dried (Na2SO4)
  6. concentrationconcentrated
  7. distillationDistillation (24 mbar, T=80-83° C.)

Sources & evidence

ORD record
ord-855596fb52db41159cd658ec321a7dd1
Source dataset
uspto-grants-2008_10
Patent number
US07432256B2

Reaction notes

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