反应详情

3-[4-[(2,4-difluorobenzyl)oxy]-6-methyl-2-oxopyridin-1(2H)-yl]-4-methylbenzoic acid (5.9 g, 15.2 mmol) (from step 3 above) was taken up in dichloromethane (25 ml). N-Bromosuccinimide was added and the reaction stirred for 14 hours. The dichloromethane was removed in vacuo and the residue was taken up in acetonitrile. The precipitate was collected on a filter pad and rinsed with acetonitrile to yield the desired product as a white solid (5.2 g, 74%). 1H NMR (300 MHz, CD3OD) δ 7.87 (dd, J=7.85, 1.61,Hz, 1H), 7.82 (d, J=1.81 Hz, 1H), 7.69 (app q, J=8.06 Hz 1H), 7.57 (d, J=8.06 Hz, 1H), 7.09 (dt, J=8.66, 2.22 Hz, 1H), 6.70 (s, 1H), 5.40 (s, 2H), 2.14 (s, 3H), 2.02 (s, 3H); ES MS m/z 464 (M+H). ES-HRMS m/z 464.0275 (M+H calcd for C21H17BrF2NO4 requires 464.0304).

1. customThe dichloromethane was removed in vacuo
2. customThe precipitate was collected on a filter pad
3. washrinsed with acetonitrile