反应详情

To 2,4-dichloro-6-methylquinoline (4.1 g, 19 mmol) in methanol (34 ml) was added KOH (1.42 g) and the resulting solution was heated under reflux for 2.5 h. The mixture was concentrated in vacuo and partitioned between ethyl acetate and half-concentrated brine. The organic layer was concentrated and chromatographed (silica gel, EtOAc:hexanes 1:5→1:3). 4-Chloro-2-methoxy-6-methylquinoline eluted first, then 2,4-dichloro-6-methylquinoline, followed by the colourless crystalline title compound, (1.97 g, 49%). δH (CDCl3) 2.52 (s, 3H), 4.05 (s, 3H), 6.71 (s, 1H), 7.53 (dd, J=8.6, 2.0, 1H), 7.83 (d, J=8.6, 1 H), 7.90 (br, s, 1 H); MS (AP+) 208 (MH+, 100%).

1. temperaturethe resulting solution was heated
2. temperatureunder reflux for 2.5 h
3. concentrationThe mixture was concentrated in vacuo
4. custompartitioned between ethyl acetate and half-concentrated brine
5. concentrationThe organic layer was concentrated
6. customchromatographed (silica gel, EtOAc:hexanes 1:5→1:3)
7. wash4-Chloro-2-methoxy-6-methylquinoline eluted first