4-Fluoroaniline → Ethyl 1-(4-fluorophenyl)imidazole-5-carboxylate

Beteiligte Stoffe

Reaktionsschritte

A mixture of 4-fluoroaniline (2.8 g, 25.0 mmol), ethyl glyoxylate (50% solution, 5.14 g, 25.0 mmol), in toluene (30 mL) was refluxed overnight. The reaction was filtered and concentrated in vacuo. To the residue was added ethanol (30 mL), toluenesulfonylmethyl isocyanide (TOSMIC) (4.9 g, 25 mmol), and potassium carbonate (6.9 g, 50.0 mmol) and the mixture was stirred at room temperature for 1 h. Brine was added and mixture was extracted with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (0-60% EtOAc in hexanes) to afford ethyl 1-(4-fluorophenyl)-1H-imidazole-5-carboxylate (14a).

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