A mixture of 2-phenyl-5-trifluoromethyl-oxazole-4-carboxylic acid (260 mg, 1 mmol), N-(5-amino-pyridin-2-yl)-N-methyl-acetamide (165 mg, 1 mmol), bromo-tri-pyrrolidino-phosphonium hexafluorophosphate (470 mg, 1 mmol), and triethylamine (202 mg, 2 mmol) in anhydrous dichloromethane (5 mL) was stirred at room temperature overnight. After the reaction was complete, the solvent and excess triethylamine were removed by evaporation. Flash chromatography (Merck silica gel 60, 230-400 mesh, 0%-40% ethyl acetate in hexane for 20 min) gave 2-phenyl-5-trifluoromethyl-oxazole-4-carboxylic acid [6-(acetyl-methyl-amino)-pyridin-3-yl]-amide as a yellow solid. LCMS calcd for C19H15F3N4O3 (m/e) 404, obsd 405 (M+H).
