166.8 mL of 6M nitric acid solution is poured into a reflux apparatus and a pressure-equalized funnel filled with 14.4 mL of 1,3-propanediol. 10 drops of the solution are added and the solution is heated gently until a reaction occurs, after the reaction subsides another 10 drops is added. This is repeated until the consumption of the reactant. Pour the solution to an evaporating dish, heat it to max 100°C with a steam bath. Continue to heat it until the solution turns brown and then clear. Leave it to dry at room temperature. Recrystallize from hot water.
Evaporation of the solution
The pure recrystallized product