Iodine → Methyl 4-amino-6-(4-chlorophenyl)-5-fluoro-3-iodopicolinate

Participants

Reaction Steps

A 250 mL round bottom flask was loaded with methyl 4-amino-6-(4-chlorophenyl)-5-fluoropicolinate (25 g, 0.08906 mol), iodine (18 g, 0.07125 mol), and periodic acid (H5IO6; 7.3 g, 0.03206 mol). CH3OH (100 mL) was added. The reaction mixture was stirred at reflux for 16 h. The reaction mixture was concentrated under vacuum and then dissolved in Et2O (500 mL). The ether solution was washed with 10% sodium thiosulfate (3×100 mL), water (3×100 mL) and then brine. The organic extracts were dried over anhydrous Na2SO4, filtered and concentrated under vacuum to give an orange solid. Crystallisation from EtOAc-hexane (3:7) gave a pale orange solid (30.5 g, 83%): mp 113.7-115.2° C.; 1H NMR (400 MHz, DMSO-d6) δ 7.84 (d, J=8.4 Hz, 2H), 7.55 (d, J=8.4 Hz, 2H), 6.73 (br s, 2H), 3.87 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ 167.50, 151.48 (d, JF-C=5 Hz), 145.95 (d, JF-C=13 Hz), 144.05 (d, JF-C=257 Hz), 140.75 (d, JF-C=9 Hz), 134.56, 133.42 (d, JF-C=5 Hz), 130.63 (d, JF-C=6 Hz), 129.02, 112.44 (d, JF-C=5 Hz), 77.52, 53.05; 19F NMR (376.5 MHz, DMSO-d6) δ −140.62; ESIMS m/z 407 ([M]+). Anal. Calcd. For C13H9ClFIN2O2: C, 38.40; H, 2.23; N, 6.89. Found: C, 38.40; H, 2.31; N, 6.85.

Provenance & Evidence