反应详情

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).

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