Hydrochloric Acid → Acetoxymethyl 8-[N-(2-chloro-4-fluorophenyl)sulfamoyl]-1,4-dioxaspiro[4.5]dec-6-ene-7-carboxylate

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Reaction Steps

1 g (2.55 mmol) of 8-[N-(2-chloro-4-fluorophenyl)sulfamoyl]-1,4-dioxaspiro[4.5]dec-6-ene-7-carboxylic acid obtained in Example 47a was dissolved in 20 ml of acetonitrile, and 0.50 ml (5.10 mmol) of bromomethyl acetate, 499 mg (1.53 mmol) of cesium carbonate and 471 mg (1.28 mmol) of tetrabutylammonium iodide were added thereto, followed by stirring for 1 hour at room temperature. 0.1 N hydrochloric acid was added to the reaction solution and the mixture was extracted with ethyl acetate. The organic layer was washed with water and dried over anhydrous magnesium sulfate, followed by concentration under reduced pressure. The residue was subjected to silica gel column chromatography (solvent; dichloromethane:methanol=49:1) to give 833 mg of the title compound as an amorphous substance (yield: 70%).

Provenance & Evidence