Triethylamine → Tert-butyl 4-(5-(2-phenyl-5-(trifluoromethyl)oxazole-4-carboxamido)pyridin-2-yl)piperazine-1-carboxylate

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Reaction Steps

4-(5-Amino-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester was mixed with 2-phenyl-5-trifluoromethyloxazole-4-carboxylic acid (771 mg, 3.0 mmol) and bromotrispyrrolidinophosphonium hexafluorophosphate (1.40 g, 3.0 mmol) in N,N-dimethylformamide (20 mL) and methylene chloride (5 mL) containing triethylamine (0.85 mL). The mixture was stirred at room temperature overnight and the solvents were evaporated. The residue was extracted with ethyl acetate and water. The organic layer was dried over sodium sulfate, filtered and concentrated. The residue was triturated with ethyl acetate and the solid was filtered to give 4-{5-[(2-phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-pyridin-2-yl}-piperazine-1-carboxylic acid tert-butyl ester (1.09 g). LC-MS calcd for C25H26F3N5O4 (m/e) 517.5, obsd 518.1 (M+H). The NMR spectrum obtained on the sample is compatible with its structure.

Provenance & Evidence