Methyl 6-iodo-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate → Methyl 6-[1-(4-chlorophenyl)-pyrazol-5-yl]-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate

Participants

Reaction Steps

Methyl 6-iodo-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate (SM1, 0.133 g, 0.304 mmol), 1-(4-chlorophenyl)-5-tributylstannyl-1H-pyrazole (0.16 g, 0.33 mmol), bis(triphenylphosphine)palladium(II) chloride (0.011 g, 0.015 mmol) and anhydrous THF (1.5 mL) in a vial were heated three consecutive times (for 55 minutes in total) in a microwave reactor (Biotage) at 130° C. until most of the iodo SM was consumed. The dark solution was concentrated to dryness with silica and applied to a silica column. Flash chromatography with ethyl acetate/n-heptane (1:4 through 2:1) gave methyl 6-[2-(4-chlorophenyl)pyrazol-3-yl]-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate (0.0915 g, 62%) as an off-white solid.

Provenance & Evidence