Nitric Acid → 4-Propyl-4H-1,2,4-triazole-3-methanol

To a mixture of 90% nitric acid (18 ml) and water (26 ml) was added sodium nitrite (0.07 g) and then 3-hydroxymethyl-5-mercapto-4-propyl-4H-1,2,4-triazole (10 g) was slowly added for 0.5 hours at 45° C. After cooling to room temperature, and sodium carbonate was slowly added thereto to adjust pH to 7 at 0° C. The reaction mixture was concentrated under reduced pressure, methanol was added to the residue, and the precipitates were removed by filtration. The mixture was concentrated under reduced pressure, dichloromethane was added to the residue, the precipitates were removed by filtration, and the filtrate was concentrated to give 3-hydroxymethyl-4-propyl-4H-1,2,4-triazole (5.95 g) as a crude product.