Hydrochloric Acid → 8-[N-(2-Chloro-4-fluorophenyl)sulfamoyl]-1,4-dioxaspiro[4.5]dec-6-ene-7-carboxylic acid

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Reaction Conditions

Reaction Steps

1.8 g (4.29 mmol) of ethyl 8-[N-(2-chloro-4-fluorophenyl)sulfamoyl]-1,4-dioxaspiro[4.5]dec-6-ene-7-carboxylate obtained in Example 1 was dissolved in 60 ml of a water-tetrahydrofuran (1:1) solution, and 900 mg (21.45 mmol) of lithium hydroxide was added thereto, followed by stirring for 7 hours at 50° C. The reaction solution was cooled with ice, it was then made acidic by addition of 1N hydrochloric acid, 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 washed with hexane to give 1.43 g of the title compound as a pale brown powder (yield: 85%).

Provenance & Evidence