反应详情

Ethyl 2-(2-methyl-3,4,6-trifluorobenzoyl)-3-cyclopropylaminoacrylate (2.6 g) is dissolved in anhydrous dioxane (26 ml) and thereto 60 % sodium hydride (0.38 g) is gradually added under ice-cooling. After stirring at room temperature for 30 minutes, the reaction mixture is poured into ice-water and extracted with dichloromethane. The extract is dried over magnesium sulfate and concentrated. The residue is added with diethyl ether and crystals are filtered, which are recrystallized from ethanol to give ethyl 1-cyclopropyl-6,7-difluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (2.0 g), m.p. 185°-187° C.

1. temperaturecooling
2. extractionextracted with dichloromethane
3. dry with materialThe extract is dried over magnesium sulfate
4. concentrationconcentrated
5. additionThe residue is added with diethyl ether and crystals
6. filtrationare filtered
7. customwhich are recrystallized from ethanol