Pyridine → HCID 58374067, compound

Participants

Reaction Steps

To a mixture of 3-phenyl-4-(trifluoromethyl)isoxazole-5-carboxylic acid (Intermediate I-3D, 3.00 g, 11.7 mmol) and pyridine (1.13 mL, 14.0 mmol) in dichloromethane (100 mL) at room temperature was added 2,4,6-trifluoro-1,3,5-triazine (cyanuric fluoride) (1.18 mL, 14.0 mmol). The reaction mixture was stirred at room temperature overnight, diluted with dichloromethane (300 mL), washed with an ice-cold solution of 0.5N aqueous hydrochloric acid (2×100 mL), and the organic layer was collected. The aqueous layer was back-extracted with dichloromethane (200 mL), and the combined organic layers were dried anhydrous sodium sulfate and concentrated to afford 3-phenyl-4-(trifluoromethyl)isoxazole-5-carbonyl fluoride (2.91 g, 11.2 mmol, 96% yield) as a yellow, viscous oil. The product was found to react readily with methanol and on analysis was characterized as the methyl ester, which had an HPLC ret. time=2.56 min. —(Condition A); LC/MS M+1=272.3 (methyl ester).

Provenance & Evidence