Pyridine → 4-{5-[(2-Phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-pyrimidin-2-yl}-piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a suspension of 2-phenyl-5-trifluoromethyloxazole-4-carboxylic acid (771 mg, 3 mmol) in methylene chloride (10 mL) was added oxalyl chloride (2M, 3 mL, 6.0 mmol) and one drop of N,N-dimethylformamide. The mixture was stirred at room temperature for 1 hr and the solvents were evaporated. The residue was treated with benzene (5 mL) and the solvents were again evaporated. The oily residue was dried in vacuum and then dissolved in methylene chloride (10 mL). The solution was cooled in an ice bath. To this solution was added a methylene chloride solution of 4-(5-amino-pyrimidin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (3 mmol) and pyridine (0.73 mL). The mixture was stirred at 0° C. for 10 minutes and room temperature for 2 hrs. After concentration, the residue was partitioned between methylene chloride and water. The organic layer was washed with aqueous citric acid solution and dried over sodium sulfate. The solvents were evaporated and the residue was dried in vacuum. The resulting material was triturated with ethyl acetate and the precipitate was filtered to give 4-{5-[(2-phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-pyrimidin-2-yl}-piperazine-1-carboxylic acid tert-butyl ester (1.38 g). LC-MS calcd for C24H25F3N6O4 (m/e) 518.5, obsd 519.1 (M+H). The NMR spectrum obtained on the sample is compatible with its structure.

Provenance & Evidence