Acetic Acid → 2-(4-(Perfluoroethoxy)phenyl)-1,3,4-oxadiazole

HRID 59872Notes

Reaction equation

HRID 59872 reaction equation
[F:1][C:2]([F:18])([O:7][C:8]1[CH:17]=[CH:16][C:11]([C:12]([NH:14][NH2:15])=[O:13])=[CH:10][CH:9]=1)[C:3]([F:6])([F:5])[F:4].[CH:19](OC)(OC)OC.C(O)(=O)C>CO>[F:1][C:2]([F:18])([O:7][C:8]1[CH:17]=[CH:16][C:11]([C:12]2[O:13][CH:19]=[N:15][N:14]=2)=[CH:10][CH:9]=1)[C:3]([F:5])([F:4])[F:6]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 9005Trimethyl orthoformateHCID 866758074-(Perfluoroethoxy)benzohydrazide

Product 1

HCID 866758082-(4-(Perfluoroethoxy)phenyl)-1,3,4-oxadiazoleYield 5.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of 4-(perfluoroethoxy)benzohydrazide (3.17 g, 11.7 mmol) in trimethyl orthoformate (11.6 mL, 106 mmol) and acetic acid (0.13 mL, 2.35 mmol) was heated at 120° C. for 5 hours. The reaction was diluted with MeOH (15 mL) and poured into a beaker containing ice water (150 mL). The white precipitate was vacuum filtered and dried in a vacuum oven to provide 166 mg of 2-(4-(perfluoroethoxy)phenyl)-1,3,4-oxadiazole as an off-white solid. An orange precipitate had formed in the aqueous filtrate and was collected by vacuum filtration and adsorbed onto silica gel. Purification by flash chromatography (0-40% EtOAc/hexanes) provided 2.02 g of 2-(4-(perfluoroethoxy)phenyl)-1,3,4-oxadiazole as an off-white solid giving a combined yield of 2.186 g (67%): mp 87-89° C.; 1H NMR (400 MHz, CDCl3) δ 8.49 (s, 1H), 8.28-8.05 (m, 2H), 7.40 (d, J=8.9 Hz, 2H); 19F NMR (376 MHz, CDCl3) δ −85.98, −87.82; ESIMS m/z 280 ([M+H]+).

Workup

  1. additionpoured into a beaker
  2. filtrationfiltered
  3. customdried in a vacuum oven

Sources & evidence

ORD record
ord-9e3c76e5e26f4805b29680fdd23ba4fc
Source dataset
uspto-grants-2016_09
Patent number
US09440964B2

Reaction notes

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