Trifluoroacetic anhydride → Ethyl 2-(2,6-difluorophenyl)-5-ethoxyoxazole-4-carboxylate

HRID 714975Notes

Reaction equation

HRID 714975 reaction equation
[F:1][C:2]1[CH:21]=[CH:20][CH:19]=[C:18]([F:22])[C:3]=1[C:4]([NH:6][CH:7]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[C:8]([O:10][CH2:11][CH3:12])=[O:9])=O.FC(F)(F)C(OC(=O)C(F)(F)F)=O>FC(F)(F)C1C=CC=CC=1>[F:1][C:2]1[CH:21]=[CH:20][CH:19]=[C:18]([F:22])[C:3]=1[C:4]1[O:9][C:8]([O:10][CH2:11][CH3:12])=[C:7]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[N:6]=1

Participants

4

Reactant 2

HCID 9845Trifluoroacetic anhydrideHCID 59587668Diethyl 2-(2,6-difluorobenzamido)malonate

Product 1

HCID 59587626Ethyl 2-(2,6-difluorophenyl)-5-ethoxyoxazole-4-carboxylateYield 45%

Reagents, catalysts & solvents 1

HCID 7368(Trifluoromethyl)benzeneSolvent

Procedure

A solution of diethyl 2-(2,6-difluorobenzamido)malonate (5.00 g, 15.9 mmol) in trifluorotoluene (16 mL) and trifluoroacetic anhydride (8.33 mL, 129.7 mmol) was heated in the microwave at 160° C. for 5 minutes. The solvent was removed in vacuo and the residue purified by silica gel column chromatography using a gradient of 0-90% EtOAc in hexanes to afford ethyl 2-(2,6-difluorophenyl)-5-ethoxyoxazole-4-carboxylate (2.11 g, 7.1 mmol, 45%) as a white solid which was used without further purification. 1H NMR (CDCl3) δ 1.39 (3H, t), 1.53 (3H, t), 4.39 (2H, q), 4.58 (2H, q), 7.02 (2H, t), 7.41 (1H, m).

Workup

  1. customThe solvent was removed in vacuo
  2. customthe residue purified by silica gel column chromatography

Sources & evidence

ORD record
ord-a9c63221bce64445906d847ec83eaa53
Source dataset
uspto-grants-2015_11
Patent number
US09187465B2

Reaction notes

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