Acetonitrile → Methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)-5-fluoropicolinate

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A 250 mL three-neck flask equipped with a reflux condenser, a nitrogen inlet and a thermocouple was charged with methyl 4-amino-3,6-dichloro-5-fluoropicolinate (9.965 g, 41.7 mmol), 2-(4-chloro-2-fluoro-3-methoxyphenyl)-1,3,2-dioxaborinane (12.74 g, 52.1 mmol) and KF (4.84 g, 83 mmol). Acetonitrile (78 mL) and water (26 mL) were added. The reaction mixture was purged with nitrogen. Pd(PPh3)2Cl2 (1.477 g, 2.10 mmol, 5 mol %) was added, and the solution was heated to 70° C. under nitrogen for 2 h. Upon cooling to room temperature, a precipitate formed which was filtered and washed with water. The precipitate was dissolved in EtOAc (ca 500 mL) and washed with water and then brine. The organic layer was dried (MgSO4) and the solvent was removed using a rotary evaporator to give an orange solid, which was dried in a vacuum oven at 50° C. (11.46 g, 76% yield): mp 169-170.5° C.; 1H NMR (400 MHz, DMSO-d6) δ 7.48 (d, J=8.4 Hz, 1H), 7.32 (t, J=7.7 Hz, 1H), 7.15 (s, 2H), 3.96 (s, 3H), 3.90 (s, 3H); 13C NMR (101 MHz, DMSO-d6) δ 164.85 (s), 153.11 (d, J=252.5 Hz), 146.29 (s), 144.52 (d, J=4.3 Hz), 143.74 (s), 142.75 (dd, J=227.1, 14.0 Hz), 136.38 (d, J=13.4 Hz), 128.58 (d, J=3.2 Hz), 125.87 (s), 125.54 (d, J=3.5 Hz), 122.89 (dd, J=13.8, 4.0 Hz), 113.01 (d, J=3.0 Hz), 61.61 (d, J=4.2 Hz), 52.70 (s); ESIMS m/z 364 ([M+H]+). Anal. Calcd for C14H10Cl2F2N2O3: C, 46.30; H, 2.78; N, 7.71. Found: C, 46.60; H, 2.68; N, 7.51.

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