Nitrogen-rich compounds from guanidine and its derivatives

4 NITROGEN-RICH COMPOUNDS FROM GUANIDINE AND ITS DERIVATIVES 

The reaction of aminoguanidine with sodium nitrite under neutral conditions yields tetra-zolylguanyltetrazene hydrate (85), a primary explosive commonly known as tetrazene. Tetrazene (85) is only formed in the absence of free mineral acid and so a common method for its preparation treats the bicarbonate salt of aminoguanidine (84) with one equivalent of acetic acid followed by addition of aqueous sodium nitrite. Tetrazene (85) is decomposed by aqueous alkali to form triazonitrosoaminoguanidine (86) which is isolated as the cuprate salt (87) on addition of copper acetate to the reaction mixture. Acidification of the copper salt (87) with mineral acid leads to the formation of 5-azidotetrazole (88) (CHN7 = 88 % N).55 56 

The reaction of aminoguanidine bicarbonate (84) with sodium nitrite in the presence of excess acetic acid produces 1,3-ditetrazolyltriazine (89), another nitrogen-rich heterocycle (C2H3N11 = 85 % N) which readily forms explosive metal salts. The reaction of aminoguanidine bicarbonate (84) with sodium nitrite in the presence of mineral acid yields guanyl azide (90), of which, the perchlorate and picrate salts are primary explosives. Guanyl azide (90) reacts with sodium hydroxide to form sodium azide, whereas reaction with weak base or acid forms 5-aminotetrazole.  

5-Aminotetrazole (91) reacts with potassium permanganate in excess aqueous sodium hydroxide to yield the disodium salt of 5-azotetrazole (92). 5-Azotetrazole is unstable and attempts to isolate it by acidification yields 5-hydrazinotetrazole (93). Diazotization of 5-aminotetrazole (91) in the presence of excess sodium nitrite yields 5-nitrotetrazole (94), a powerful explosive whose mercury and silver salts are primary explosives.  

Hydrolysis of N -nitro-N-methylnitroguanidine (101) and Al-nitroso-N-methylnitrogu-anidine (102) with aqueous potassium hydroxide results in the formation of potassium nitrocyanamide. Addition of acidic silver nitrate solution to these reaction mixtures leads to 

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