Triphosgene → 8-Chloro-7-(4-methylphenyl)[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

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Reaction Steps

To a stirred solution of triphosgene (2.64 g, 8.9 mmol) in THF (25 mL) at room temperature under argon was added 1-(3-chloro-4-p-tolylpyridin-2-yl)hydrazine (0.692 g, 3.0 mmol). The reaction mixture was stirred at room temperature for 16 h. Analysis by HPLC/MS indicated that starting material had been consumed. Water (25 mL) was added while stirring. The resulting suspension was heated at 100° C. for 40 h. Upon cooling to room temperature, the desired product was filtered and further washed with water (15 mL×2). After drying in a vacuum oven under reduced pressure overnight, 562 mg of the title compound was obtained as a white solid. HPLC/MS: retention time=2.98 min, [M+H]+=260.

Provenance & Evidence