Chlorosuccinimide → 3-[3-chloro-4-[(2,4-difluorobenzyl)oxy]-6-methyl-2-oxopyridin-1(2H)-yl]-4-methylbenzoic acid

Participants

Reaction Steps

3-[4-[(2,4-Difluorobenzyl)oxy]-6-methyl-2-oxopyridin-1(2H)-yl]-4-methylbenzoic acid (from above) (7.5 g, 19.4 mmol) and NCS (2.6 g, 19.4 mmol) were taken up in 65° C. dichloroethane (100 ml). A catalytic amount of dichloroacetic acid (2 drops) was added. After two hours the solvent was removed in vacuo and the residue was taken up in diethyl ether. The precipitate was collected on a filter pad and then taken up in 50% ethyl acetate/hexanes to remove residual succinimide. The precipitate was collected on a filter pad and then dried in vacuo to produce a white powder (4.2 g, 52%). 1H NMR (300 MHz, CD3OD) δ 8.10 (dd, J=7.85) 1.81 Hz, 1H), 7.83 (d, J=8.26, 1.81 Hz, 1H), 7.40 (app q, J=8.26 Hz, 1H), 7.58 (d, J=7.85 Hz, 1H), 7.13-7.06 (m, 2H), 6.74 (s, 1H), 5.40 (s, 2H), 2.14 (s, 3H), 2.04 (s, 3H); ES-MS m/z 420 (M+H). ES-HRMS m/z 420.0786 (M+H calcd for C21H17ClF2NO4 requires 420.0809).

Provenance & Evidence