反应详情

Heat a solution of 2 g (8 mmol) of ethyl 7-acetyl-2,3-dihydro-1,4-benzodioxin-2-carboxylate and 3.05 g (17.7 mmol) of meta-chloro-perbenzoic acid in 30 cm3 of methylene chloride at 50° C. for 18 hours under a nitrogen atmosphere. After cooling, removing by filtration the benzoic acid formed, and washings with aqueous solutions of sodium hydrogen carbonate and then sodium chloride, the reaction mixture is concentrated to dryness under reduced pressure and the crude product obtained is purified by chromatography on a silica column (eluant:petroleum ether/diethyl ether, 70:30). Ethyl 7-acetoxy-2,3-dihydro-1,4-benzodioxin-2-carboxylate is thereby obtained in a yield of 75%. ##STR34##

1. temperatureAfter cooling
2. customremoving by filtration the benzoic acid
3. customformed
4. washwashings with aqueous solutions of sodium hydrogen carbonate
5. concentrationsodium chloride, the reaction mixture is concentrated to dryness under reduced pressure
6. customthe crude product obtained
7. customis purified by chromatography on a silica column (eluant:petroleum ether/diethyl ether, 70:30)