Synthesis of New Pyrimidine-2,4,6(1H,3H,5H)-trione Derivatives

Abstract

The condensation of 5-acetylpyrimidine-2,4,6(1H,3H,5H)-trione with 3-fluoro-, 4-fluoro-, and 2-methoxy-3,5-dichlorobenzaldehydes and methyl (4-formyl-2- oxo-2H-chromen-7-yl)carbamate in BuOH in the presence of piperidine and acetic acid for 4 h under reflux gave 5-[(E)-3-aryl-2-propenoyl]pyrimidine--2,4,6(1H,3H,5H)-triones) and methyl N-{2-oxo-4-[(E)-3-oxo-3-(2,4,6-trioxohexahydropyrimidin-5-yl)-1-propenyl]-2H-chromen-7-yl}carbamate. The reactions of 3-methoxy-4-hydroxy-, 3,5-dimethoxy-4-hydroxybenzaldehydes with 5-acetyl-pyrimidine-2,4,6(1H,3H,5H)-trione in dioxane in the presence of boron trifluoride etherate at room temperature forms the corresponding chalcones within 48 h. The corresponding imines and 5-arylidene derivatives were prepared by the condensation of barbituric acid with alkyl C-nitroso phenylcarbamates in methanol and hydroxy-substituted benzaldehydes in water. The condensation of 5-[(4-hydroxy-3,5-dimethoxyphenyl)methylene]pyrimidine-2,4,6(1H,3H,5H)-triones with aminoguanidine bicarbonate results in the formation of 7-hydrazinyl-5-(4-hydroxy-3,5-dimethoxyphenyl)pyrimido[4,5-d]pyrimidine-2,4(1H,3H)-dione. The cyclocondensation of pyrimidine-2,4,6(1H,3H,5H)-trione with methyl N-{3-[(E)-3-(4-methoxyphenyl)-2-propenoyl]phenyl}carbamate in acetic acid in the presence of P₂O₅ provided methyl {3-[5-(4-methoxyphenyl)-2,4-dioxo-1,3,4,5-tetrahydro-2H-pyrano[2,3-d]pyrimidin-7-yl]phenyl}carbamate.