The cyclization of ethyl 2-formyl-3-(3,4-methylenedioxyphenyl)propionate (I) with nitroguanidine (II) by means of sodium methoxide in refluxing methanol gives 2-nitroamino-5-(3,4-methylenedioxybenzyl)-4-pyrimidone (III), which is then condensed with 2-(5-methyl-4-imidazolylmethylthio)ethylamine (IV) in refluxing ethanol.

The cyclization of ethyl 2-formyl-3-(3,4-methylenedioxyphenyl)propionate (I) with nitroguanidine (II) by means of sodium methoxide in refluxing methanol gives 2-nitroamino-5-(3,4-methylenedioxybenzyl)-4-pyrimidone (III), which is then condensed with 2-(5-methyl-4-imidazolylmethylthio)ethylamine (IV) in refluxing ethanol.

The cyclization of ethyl 3-(3,4-ethylenedioxyphenyl)propionate (V), ethyl formate (VI) and thiourea (VII) by means of Na in ether and ethanol gives 5-(3,4-methylenedioxyphenyl)-2-thiouracil (VIII), which by reaction with methyl iodide and NaOH in ethanol-water is converted into 5-(3,4-methylenedioxybenzyl)-2-methylthio-4-pyrimidone (IX). Finally, this compound is condensed with (IV) by heating at 150 C.

The cyclization of ethyl 3-(3,4-ethylenedioxyphenyl)propionate (V), ethyl formate (VI) and thiourea (VII) by means of Na in ether and ethanol gives 5-(3,4-methylenedioxyphenyl)-2-thiouracil (VIII), which by reaction with methyl iodide and NaOH in ethanol-water is converted into 5-(3,4-methylenedioxybenzyl)-2-methylthio-4-pyrimidone (IX). Finally, this compound is condensed with (IV) by heating at 150 C.