反应详情

A mixture of 3,4-dibromo-2,2-bis(fluoromethyl)-6-trifluoromethyl-3,4-dihydro-2H-1-benzopyran (10.72 g), a 2 N aqueous solution of sodium hydroxide (60 ml) and dioxane (100 ml) was stirred at room temperature for 2 hours. To the reaction mixture, 2 N HCl was added, followed by extraction with ethyl acetate; the resulting orgnaic layers were combined, washed with a saturated aqueous solution of sodium chloride, dried with anhydrous sodium sulfate and concentrated under reduced pressure; the resulting residue was subjected to silica gel column chromatography (eluent; hexane/ethyl acetate=10/1) to give 4-bromo-2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran (8.18 g).

1. extractionfollowed by extraction with ethyl acetate
2. washwashed with a saturated aqueous solution of sodium chloride
3. dry with materialdried with anhydrous sodium sulfate
4. concentrationconcentrated under reduced pressure