Chlorodifluoromethane → 4-Difluoromethyl-3-methyl-1-phenyl-1H-1,2,4-triazol-5(4H)-one

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Reaction Steps

This compound was prepared in the manner of Example 3, with 50.0 grams of 4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-1,2,4-triazole (0.286 mole--1.0 equiv.), 11.4 grams (0.286 mole--1.0 equiv.) of sodium hydroxide in 50 mL of water, 9.9 grams (0.071 mole--0.25 equiv.) of potassium carbonate, and 37.1 grams (0.429 mole--1.5 equiv.) of chlorodifluoromethane in 333 mL of tetraglyme (% wt/vol. triazole to solvent--15%) as reagents. A yield of 63.2 grams of 96.3% pure 4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-1,2,4-triazole (96.6% yield) was obtained. GC analysis of the product indicated the presence of about 0.9% O-isomer by-product.

Provenance & Evidence