Sulfuric Acid → 3-Ethyl 3,5-isoxazoledicarboxylate

Beteiligte Stoffe

Reaktionsschritte

A 2M solution of the Jone's reagent was prepared by addition of 6 g of chromium (VI) oxide to a solution of H2SO4 (8.1 g) in water (25.5 mL). To a solution of ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate (4.00 g; 23.37 mmol) in acetone in an ice bath was added dropwise during a period of 20 min the Jone's reagent (27.71 mL; 51.42 mmol). The reaction mixture was then stirred at room temperature for additional 3.5 hours. 5 mL of 2-propanol were added and the stirring continued for further 1 hour. The solution became green. Brine (60 mL) and ethyl acetate (150 mL) were added to the reaction mixture and after separation, the organic layer was washed with an aqueous solution of sodium bisulphite (15 g in 100 mL of H2O) and with brine (100 mL). The organic layer was dried over magnesium sulfate. The evaporation of the solution furnished 3.03 g (70%) of 3-(ethoxycarbonyl)isoxazole-5-carboxylic acid as a white solid.

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