Methyl iodide → HCID 19365515, compound

Participants

Reaction Steps

First, 23.3 g of 3-(2,4-difluorophenyl)-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (compound 1-1004) was dissolved in 150 ml of acetone, to which 17.5 g of potassium carbonate and 14.3 g of methyl iodide were added, and the mixture was stirred at room temperature for 15 hours. After completion of the reaction, most of the acetone was distilled out under reduced pressure, and the residue was poured into water, followed by extraction with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography (eluent, hexane/ethyl acetate=19:1), which afforded 16.1 g of 3-(2,4-difluorophenyl)-2-methoxy-6-trifluoromethylpyrazine (m.p., 55.3° C.) as the earlier eluted O-methylated compound and 7.13 g (yield, 29%) of 3-(2,4-difluorophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (present compound 1-10; m.p., 73.0° C.) as the later eluted desired compound.

Provenance & Evidence