Potassium Carbonate → 1-[4-chloro-2-fluoro-5-(5-hydroxypyridin-2-yloxy)-phenyl]-4-difluoromethyl-4,5-dihydro-3-methyl,1,2,4-triazol-5(1H)-one

Participants

Reaction Steps

To a stirred, cold (ice bath) solution of 0.67 g (0.0048 mole) of potassium carbonate in 20 mL of trifluoroacetic acid was added 4.7 g (0.097 mole) of 2-[2-chloro-4-fluoro-5-(4-difluoromethyl-4,5-dihydro -3-methyl-5-oxo-1H-1,2,4-triazol-1-yl)phenoxy]pyridine-5-diazonium tetrafluoroborate. The reaction mixture was allowed to warm to room temperature and was then heated at reflux for 5.5 hours. The mixture was cooled to room temperature, diluted with 50 mL of water, and the whole was extracted with four portions of methylene chloride. The extracts were combined, dried over anhydrous magnesium sulfate, and filtered. The filtrate was evaporated under reduced pressure to give a red oil which was purified by column chromatography on silica gel. Elution with n-hexane:ethyl acetate (2:1) gave 3.3 g of 1-[4-chloro-2-fluoro-5-(5-hydroxypyridin-2-yloxy)-phenyl]-4-difluoromethyl-4,5-dihydro -3-methyl,1,2,4-triazol-5(1H)-one as a solid, m.p. 179°-181° C.

Provenance & Evidence