Hydrochloric Acid → 2-(Propylthio)pyrimidine-4,6-diol

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Reaction Steps

Water (670 ml) was added to 2-thiobarbituric acid (200 g). The resulting mixture was stirred and sodium hydroxide (126.3 g) was added in portions. The mixture was stirred for 40 min. then diluted with water. 1-Methyl-2-pyrrolidinone (400 ml) and 1-iodopropane (140.9 ml) were then added. The resulting slurry was stirred at 20° C. for 22 h. The pH of the mixture was then adjusted to 6.5 by addition of 1M HCl (600 ml) over 30 min, then to pH 2.5 by the addition of 6 M HCl (180 ml) over a further 30 min. The resulting slurry was stirred for 18 h and the product was isolated by filtration and washed successively with water (4×100 ml), ethanol (200 mm) and water (2×200 ml). The product was dried under reduced pressure overnight at 50° C. to yield the title product as a white powder (185 g).

Provenance & Evidence