反应详情

4,6-dichloro-1-(4-methoxybenzyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carbonitrile (95) (8.2 g, 22.70 mmol) in neat TFA was refluxed for 24 h. The solution was cooled and excess TFA was distilled off under reduced pressure. The residue was taken in water, basified by solid NaHCO3 and filtered. The solids were washed with excess water and dried to yield 5.2 g (96%) of 4,6-dichloro-2-oxo-1,2-dihydro-[1,8]-naphthyridine-3-carbonitrile (97) as yellow solids. MP: 247° C.; 1H-NMR (DMSO-d6): δ 8.45 (dd, J=2.4 Hz, 1H), 8.82 (d, J=2.4 Hz, 1H), 13.17 (S, 1H); EIMS: 240 (M).

1. temperatureThe solution was cooled
2. distillationexcess TFA was distilled off under reduced pressure
3. filtrationfiltered
4. washThe solids were washed with excess water
5. customdried