Methylmalonic Acid → 1,3,5-Trimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione

Participants

Reaction Conditions

Reaction Steps

75 g (0.85 mol) of 1,3-dimethylurea and 102 g (0.86 mol) of methyl malonic acid were dissolved in 300 ml of glacial acetic acid at 65° C. To the solution was added 330 ml of acetic anhydride, the temperature was gradually raised and the mixture was refluxed by heating at 90° C. for 6 hours. The reaction solution was concentrated under reduced pressure, and benzene was added to the residue. The crystals thus-deposited were collected by filtration and recrystallized from benzene to obtain 60 g of 1,3,5-trimethylbarbituric acid. Yield: 42%, Melting Point: 83° to 85° C.

Provenance & Evidence