Sodium Hydroxide → Xanthine

Participants

Reaction Steps

22.6 g (0.1 mole) of 1-propyl-5-acetylamino-6-aminouracil (II) (R3 =methyl, R8 =methyl) are suspended under nitrogen in 200 ml of anhydrous dimethyl formamide (DMF) . 21.7 g (0.13 mole) of 5-bromo-l-pentanol are then added, after which 6 g (0.15 mole) of powder-form solid NaOH are added with stirring in portions of 1 g at a time at intervals of 1 hour. After the third addition, the suspension is completely dissolved. The solution is left standing overnight to complete the reaction. The solvent is evaporated in a rotary evaporator at 40° C./0.1 mm Hg. The oily residue, which is the uracil (III) (R1 =5-hydroxypentyl, R3 =propyl , R8 =methyl), which is not purified, is dissolved in 100 ml of 10% NaOH and the solution heated under reflux for 2 hours. The solution is then cooled in a ice bath and neutralized to pH 5 with acetic acid. The product precipitated is filtered, washed with cold water and then dried in a vacuum oven. The dried product is dissolved in 500 ml of ethanol and the solution is decoloured overnight with active carbon. The product is precipitated by addition of 1 liter of water, filtered and the treatment with active carbon repeated. The dried product is recrystallized twice with 120 ml of dioxane. Yield: 23.5 g (80%); colourless crystals; Mp. 184-185° C.

Provenance & Evidence