5-Aminotetrazole [4418-61-5-A] CH3N5
In a 1000-ml beaker, add 163.3 g (1.2 mol) of aminoguanidine bicarbonate to 120 ml of distilled water. While stirring constantly, slowly add 379.1 g (2.6 mol) of 25% hydrochloric acid (strong foaming!). The temperature of the solution must not exceed 40 °C during the addition of the acid; a cooling bath is recommended. Subsequently, add 321.7 g (1.2 mol) of a 26% aqueous sodium nitrite solution (82.8 g of sodium nitrite in 239 ml of water) dropwise. After allowing the solution to stand overnight at room temperature, add 48.5 g (1.2 mol) of 99% pure sodium hydroxide. By adding the sodium hydroxide, let the temperature of the reaction mixture rise to 85 °C and maintain it at this temperature for 3 hours. After this period, cool the solution to 3 °C, causing the 5-aminotetrazole to crystallize. The filtered crystals (approx. 124 g) are dissolved in 372 ml of water at 85 °C. After cooling the solution to 3 °C, the wet crystalline 5-aminotetrazole hydrate is filtered off (approx. 103.8 g). The crystals are dried under reduced pressure for one hour. The yield is 97.7 g of 99.9% pure 5-aminotetrazole monohydrate (CH3N5·H2O) with a melting point of 207-209 °C, corresponding to 72.9% of the theoretical yield.
Source: The synthesis details are based on a modified version of US Patent 5,594,146.
Delivered by: Mephisto
Last updated: 01/11/2004
Other name: 5-ATZ