1,2-Difluoro-4-nitrobenzene → 1-(2-fluoro-4-nitrophenyl)-5-methyl-1H-1,2,4-triazole

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Reaction Steps

3,4-Difluoronitrobenzene (514 mg, 3.23 mmol), 3-methyl-1H-1,2,4-triazole (325 mg, 3.72 mmol) and di-potassium hydrogen phosphate trihydrate (1.49 g, 6.46 mmol) in dimethyl sulfoxide (1.5 mL) were stirred for 6 hours at 70° C. The mixture was concentrated in vacuo; the residue was diluted in water and extracted three times with ethyl acetate. The combined organic layers were washed four times with water, twice with brine, dried with magnesium sulfate and evaporated. Column chromatography (30 g silica, heptane/ethyl acetate 1:1 v/v) afforded the title compound (160 mg, 22%) as white crystals MS ISP (m/e): 223.2[(M+H)+]. 1H NMR (CDCl3, 300 MHz): δ (ppm)=8.22 (m, 2H), 8.04 (s, 1H), 7.74 (dd, 1H), 2.48 (d, 3H). Mp 56-58° C.

Provenance & Evidence