Acetonitrile → Methyl 4-amino-3-chloro-6-(2,5-difluoro-4-(trimethylsilyl)phenyl)-5-fluoropicolinate

Participants

Reaction Conditions

Reaction Steps

In a microwave vessel, a suspension of (2,5-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)trimethylsilane (see, e.g., WO 2013003740 A1) (0.6 g, 1.922 mmol), methyl 4-amino-3,6-dichloro-5-fluoropicolinate (Head B) (0.383 g, 1.601 mmol), bis(triphenyl phosphine)palladium(II) chloride (0.112 g, 0.160 mmol) and sodium carbonate (0.204 g, 1.922 mmol) in a 3:1 mixture of acetonitrile (4.00 mL) and water (1.334 mL) was stirred under microwave irradiation (120° C., 20 min). The reaction mixture was poured into an half saturated brine solution and was extracted with EtOAc (3×). The combined organic layers were dried over Na2SO4, filtered and concentrated. The residue was purified by preparative reverse phase HPLC (water/acetonitrile gradient) to afford the title compound as a white solid (0.271 g, 0.697 mmol, 43.5%): 1H NMR (400 MHz, CDCl3) δ 7.23 (dd, J=7.8, 5.1 Hz, 1H), 7.13 (dd, J=9.3, 4.0 Hz, 1H), 4.95 (s, 2H), 3.98 (s, 3H), 0.33 (d, J=0.8 Hz, 9H); 19F NMR (376 MHz, CDCl3) δ −106.81, −106.87, −121.20, −121.25, −121.29, −121.35, −137.32, −137.41; ESIMS m/z 389 ([M+H]+).

Provenance & Evidence