2-Fluoro-3-methoxyphenylboronic acid → 1-(2,6-Difluorobenzyl)-2,6-dimethyl-3-(2-fluoro-3-methoxyphenyl)-5-ethoxycarbonyl-4-pyridone

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Reaction Conditions

Reaction Steps

1-(2,6-Difluorobenzyl)-2,6-dimethyl-3-bromo-5-ethoxycarbonyl-4-pyridone (1.5 g, 3.7 mmol) was evacuated in a pressure vessel with 2-fluoro-3-methoxyphenyl boronic acid (764 mg, 4.5 mmol) and tetrakis(triphenylphosphine) palladium (0) (428 mg, 370 μmol). A mixture of benzene/ethanol/1,2-dimethoxyethane (74 ml in a 10/1/11 ratio) and barium hydroxide (saturated aqueous, about 0.5M) was then added under vacuum, the vessel sealed under N2, and the reaction stirred at 90° C. for twelve hours, protected from light. The organic layer was concentrated and purified using flash silica chromatography (EtOAc/hexanes-1/4 to MeOH/CH2Cl2-2/98), with the product eluting as the third spot. The product was dried as an amber oil (1.12 g, 2.5 mmol, 68%). 1H NMR (CDCl3, 300 MHz) δ 6.80-7.80 (m, 6H), 5.29 (s, 2H), 4.37-4.33 (m, 2H), 3.87 (s, 3H), 3.38 (s, 3H), 2.26 (s, 3H), 1.35 (t, 3H); LCMS=446 (MH+).

Provenance & Evidence