反应详情

To a mixture of 4.0 g of 6-amino-2,2-bisfluoromethyl-2H-1-benzopyran-4-carboxylic acid ethyl ester, 1.66 g of sulfuric acid and 40 ml of water was added a mixture of 1.09 g of sodium nitrite, 10 ml of methylene chloride and 10 ml of water with ice-cooling, and the reaction mixture was stirred with ice-cooling for 10 minutes. The reaction mixture was further combined with a mixture of 2.85 g of potassium iodide and 5 ml of water and stirred at room temperature for 1.5 hours. The reaction mixture was combined with water and extracted with methylene chloride. The organic layer was washed with an aqueous 20% sodium sulfite solution and saturated saline, then dried over sodium sulfate and concentrated under reduced pressure, and the resulting residue was subjected to silica gel column chromatography (eluent; ethyl acetate:hexane=1:1) to give 3.67 g of 2,2-bisfluoromethyl-6-iodo-2H-1-benzopyran-4-carboxylic acid ethyl ester; m.p. 89-90° C.;

1. additionwas added
2. temperaturecooling
3. temperaturecooling for 10 minutes
4. stirringstirred at room temperature for 1.5 hours
5. extractionextracted with methylene chloride
6. washThe organic layer was washed with an aqueous 20% sodium sulfite solution and saturated saline
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated under reduced pressure