反应详情

Propan-2-yl 4-amino-5-fluoro-6-(4-chloro-2-fluoro-3-methoxyphenyl)picolinate (500 mg, 1.402 mmol) was dissolved in dichloromethane (3.2 mL). N-Bromo-succinimide (299 mg, 1.682 mmol) was added, and the solution was stirred at ambient temperature for 20 h. The reaction mixture was then concentrated to dryness. The residue was purified by chromatography (40 g silica gel column; 0-70% EtOAc-hexanes) to give a tan solid (504 mg, 83%): 1H NMR (400 MHz, DMSO-d6) δ 7.47 (dd, J=8.5, 1.6 Hz, 1H), 7.29 (dd, J=8.5, 7.1 Hz, 1H), 7.01 (s, 2H), 5.22-5.10 (m, 1H), 3.93 (d, J=0.9 Hz, 3H), 1.32 (d, J=6.3 Hz, 6H); EIMS m/z 350.

1. concentrationThe reaction mixture was then concentrated to dryness
2. customThe residue was purified by chromatography (40 g silica gel column; 0-70% EtOAc-hexanes)