Dimethyl Sulfate → HCID 23042093, compound

Participants

Reaction Steps

A mixture of 3.75 g (11.0 mmol) of 5-(2,6-difluorophenyl)-2-(α,α,α-trifluoro-o-tolyl)-2,4-dihydro-3H-1,2,4-triazol-3-one, 1.05 g (11.0 mmol) of dimethyl sulfate and 3.04 g (22.0 mmol) of potassium carbonate in acetone is stirred at the reflux temperature for 16 hours. The insoluble constituents are then filtered off and the evaporated residue is subjected to chromatography on silica gel using ethyl acetate/n-hexane (1:4) as the eluent. As the first fraction there is isolated the apolar secondary component 3-(2,6-difluorophenyl)-5-methoxy-1-(α,α,α-trifluoro-o-tolyl)-1H-1,2,4-triazole, m.p. 118°-119° C.; mass spectrum: 355(75), 298(39), 159(100); 1H-NMR (CDCl3): 4.13 (s, OCH3). After further elution with ethyl acetate/n-hexane (2:3) and subsequent recrystallization from diethyl ether/n-hexane there is obtained pure 5-(2,6-difluorophenyl)-4-methyl-2-(α,α,α-trifluoro-o-tolyl)-2,4-dihydro-3H-1,2,4-triazol-3-one, m.p. 98°-99° C., IR spectrum: 1708 cm-1 ; mass spectrum: 355(75), 298(32), 159(100); 1H-NMR (CDCl3): 3.30 (s,N-CH3).

Provenance & Evidence