Hexane → Propan-2-yl 4-amino-3-chloro-5-fluoro-6-(4-chloro-2-fluoro-3-methoxyphenyl)picolinate

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Reaction Steps

Propan-2-yl 4-amino-5-fluoro-6-(4-chloro-2-fluoro-3-methoxyphenyl)picolinate (3.065 g, 8.59 mmol) was dissolved in sulfuryl chloride (150 mL). The solution was stirred under nitrogen at room temperature for 8 h. During this time, a white precipitate formed. Hexane (100 mL) was added, and the mixture was stored overnight at −20° C. The product was filtered, washed with hexane and then slurried in EtOAc (100 mL). The organic suspension was neutralized with satd aq NaHCO3 solution, which caused all solids to dissolve. The organic layer was separated and washed with 10% aq NaHSO3 solution and brine, dried (MgSO4), and concentrated under reduced pressure to give a white solid (1.962 g, 58%): mp 109-111° C.; 1H NMR (400 MHz, CDCl3) δ 7.25 (m, 2H), 5.32 (septet, J=6.3 Hz, 1H, CHMe2), 5.07 (br s, 2H), 3.97 (d, JF-H=1.0 Hz, 3H, OMe), 1.40 (d, J=6.3 Hz, 6H, CHMe2); 19F NMR (376 MHz, CDCl3) δ −128.16 (dd, JF-F=33.3 Hz, JF-H=2.5 Hz, phenyl F), −138.35 (d, JF-F=33.4 Hz, pyridine F5).

Provenance & Evidence