反应详情

A solution of 1.52 9 of 4-(3-chloro-5-trifluoromethylpyridin-2-yloxy)-3,5-dimethylaniline, 1.75 g of methyl 2-methyl-3-oxopentanoate, and 0.92 g of p-toluenesulfonic acid dissolved in 49 mL of xylene was heated under reflux for 8 hr. This reaction solution was cooled, and the precipitated crystals were then collected by filtration and were washed with n-hexane and distilled water and were dried to give 2.56 g of 6-(3-chloro-5-trifluoromethylpyridin-2-yloxy)-2-ethyl-4-hydroxy-3,5,7-trimethyl-quinoline. Dimethylacetamide (30 mL) was then added to 1.97 g of the crystals thus obtained, and 0.38 g of 60% sodium hydride and 0.9 g of methyl chloroformate were added thereto at room temperature. The mixture was stirred at room temperature for 2 hr, and ethyl acetate and distilled water were then added. The organic layer was washed with brine and was then concentrated under the reduced pressure. The crude product was purified by column chromatography on silica gel (BW300, manufactured by Fuji Sylysia Chemical Ltd., solvent: n-hexane /ethyl acetate) to give 1.25 g of 4-methoxycarbonyloxy-6-(3-chloro-5-trifluoromethylpyridin-2-yloxy)-2-ethyl-3,5,7-trimethylquinoline (yield 55.6%).

1. temperaturewas heated
2. temperatureunder reflux for 8 hr
3. temperatureThis reaction solution was cooled
4. filtrationthe precipitated crystals were then collected by filtration
5. washwere washed with n-hexane
6. distillationdistilled water
7. customwere dried