反应详情

The methyl 4-acetamido-3-(benzyloxy)-6-(4-chloro-2-fluoro-3-methoxyphenyl)-picolinate produced in the first step was dissolved in ethyl alcohol (EtOH; 100 mL), and a catalytic amount of palladium hydroxide (Pd(OH)2) in carbon was added (2 spatula tips). The reaction mixture was stirred under a hydrogen atmosphere for 24 h, and the palladium was removed by filtration. The filtrate was concentrated, and the residue was purified by flash chromatography (SiO2; 0-50% EtOAc/hexane gradient) to provide the title compound as a white solid (0.431 g, 29% yield for the two steps): mp 168-172° C.; 1H NMR (400 MHz, CDCl3) δ 11.28 (s, 1H), 8.93 (d, J=1.6 Hz, 1H), 7.98 (s, 1H), 7.49 (dd, J=8.5, 7.6 Hz, 1H), 7.23 (dd, J=8.6, 1.8 Hz, 1H), 4.07 (s, 3H), 3.99 (d, J=1.1 Hz, 3H), 2.30 (s, 3H); ESIMS m/z 369 ([M+H]+).

1. customthe palladium was removed by filtration
2. concentrationThe filtrate was concentrated
3. customthe residue was purified by flash chromatography (SiO2; 0-50% EtOAc/hexane gradient)