反应详情

In 1 ml of dioxane were dissolved 100 mg of ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-methoxynicotinoyl]acetate, 55 mg of acetic anhydride and 60 mg of ethyl ortho-formate, and the resulting solution was subjected to reaction under reflux for 7 hours. Subsequently, the reaction mixture was added to a mixture of 3 ml of ethyl acetate and 3 ml of water, and the organic layer was separated, washed successively with 3 ml of water and 3 ml of saturated aqueous sodium chloride solution, and then dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and to the crystalline material thus obtained was added 1 ml of diethyl ether, after which crystals were collected by filtration to obtain 45 mg (yield 43.8%) of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate. The physical properties of this compound were identical with those of the compound obtained in Example 41.

1. customthe resulting solution was subjected to reaction
2. temperatureunder reflux for 7 hours
3. customthe organic layer was separated
4. washwashed successively with 3 ml of water and 3 ml of saturated aqueous sodium chloride solution
5. dry with materialdried over anhydrous magnesium sulfate
6. customThe solvent was removed by distillation under reduced pressure
7. customto the crystalline material thus obtained
8. filtrationafter which crystals were collected by filtration