Malonic Acid → 1-Benzyl-3-phenylbarbituric acid

Participants

Reaction Conditions

Reaction Steps

In a 300-ml glass flask equipped with a thermometer, a reflux condenser and a stirrer, 5.0 g of N-benzyl-N′-phenylurea synthesized in Exemplary Synthesis 1, 2.5 g of malonic acid, 20 ml of toluene, and 5.6 g of acetic anhydride were put, the content was heated under stirring so as to adjust the inner temperature to 80° C., and kept under stirring at 80° C. for 3 hours. The content was then cooled to 50° C., washed with 15 ml of water, and the aqueous phase was discarded. The organic layer was kept under stirring at room temperature, and 5 ml of isopropanol was dropped therein. The content was further stirred at 10° C. or below for 0.5 hours, filtered under suction to collect a deposited crystal, the crystal was washed with cold isopropanol, and dried, to thereby obtain 4.6 g of 1-benzyl-3-phenylbarbituric acid as an intermediate.

Provenance & Evidence