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

Participants

Reaction Conditions

Reaction Steps

2-Thiobarbituric acid (100 g) was added to the water (250 ml) under stirring, followed by the addition of a solution of sodium hydroxide pellets or flakes (63.13 g) in water (147.35 ml) over a period of 15 to 20 minutes at 20-25° C. The resulting mass was stirred for 40 minutes at 20-25° C., followed by the addition of water (200 ml). The reaction temperature was raised to 30-35° C., followed by addition of methanol (200 ml), propyl iodide (123.36 g) and tetrabutyl ammonium bromide (1.0 g) under stirring at 30-35° C. The resulting reaction mixture was stirred for 24 hours at 30-35° C. The reaction was monitored by thin layer chromatography. After completion of reaction, the pH of the reaction mixture was adjusted to less than 2.0 by the addition of dilute hydrochloric acid (prepared by mixing of 60 ml of concentrated hydrochloric acid with 140 ml of water). The resulting slurry was stirred for 15 hours, and the product was isolated by filtration and washed successively with water (4×200 ml) and cyclohexane (200 ml). The wet product was dried under reduced pressure at 40-45° C. to produce 85 g of 2-propylthio-pyrimidine-4,6-diol as a white powder (Yield: 65.7%; Purity by HPLC: 90.96 area-%).

Provenance & Evidence