92664-05-6

General procedure for the synthesis of 1-cyano-3-ethoxy-2,3-dioxopropan-1-one potassium salt from diethyl oxalate and acetonitrile: Diethyl oxalate (5.06 g, 34.62 mmol, 1.00 eq.) was dissolved in 20 mL of acetonitrile, and potassium tert-butanolate (3.90 g, 34.76 mmol, 1.12 eq.) was added in batches at room temperature. The reaction mixture was stirred at room temperature for 1.5 hours. At the end of the reaction, the resulting solid product was collected by filtration. 5.09 g (82% yield) of the target product 1-cyano-3-ethoxy-2,3-dioxopropan-1-one potassium salt was finally obtained as a yellow solid.

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