Potassium Carbonate → 1-(3-Nitrobenzyl)-6-(3,4,5-trimethoxyphenyl)-1,3-dihydroimidazo[4,5-b]pyrazin-2-one

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Reaction Conditions

Reaction Steps

To a solution of 6-bromo-1-(3-nitrobenzyl)-1,3-dihydroimidazo[4,5-b]pyrazin-2-one (95 mg, 0.27 mmol), 3,4,5-trimethoxyphenyl boronic acid (65 mg, 0.30 mmol) and potassium carbonate (120 mg, 0.88 mmol) in degassed 20% aq. dioxane (2.5 mL) was added dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane adduct (24 mg, 0.029 mmol) under an argon atmosphere. The mixture was stirred at 95° C. overnight, then cooled to room temperature and concentrated under reduced pressure. Purification of the resultant residue by flash chromatography [silica gel; hexanes/ethyl acetate (2:1)] afforded 1-(3-nitrobenzyl)-6-(3,4,5-trimethoxyphenyl)-1,3-dihydroimidazo[4,5-b]pyrazin-2-one as a white solid (82 mg, 70%). 1H NMR (300 MHz, CDCl3): δ 8.48 (t, J=2.2 Hz, 1H), 8.19 (dd, J=7.5 and 2.2 Hz, 1H), 7.91 (dd, J=7.5 and 2.2 Hz, 1H), 7.55 (t, J=7.5 Hz, 1H), 7.16 (s, 2H), 5.30 (s, 2H), 4.00 (s, 6H), 3.92 (s, 3H). MS: 438.1 (M+H).

Provenance & Evidence