Azides, guanyl

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. ... 

Guanyl Azide Derivatives and Salts. See Azidoformamidine under Formamidine in Vol 6, pp FI68-L to F169-R... 

The formation of guanyl azide (IV) at the first stage may account for the formation of tetrazene by the action of nitrous acid on aminoguanidine, i.e. by Hoffmann synthesis. 

Guanyl azide is then isomerized to aminotetrazole (V) which undergoes diazo-tization and couples with aminoguanidine as stated above. 

In the presence of mineral acids, sodium nitrite reacts in a different manner with aminoguanidine, and guanyl azide is formed. 

This substance forms salts with acids, and was first isolated in the form of its nitrate. The nitrate is not detonated by shock but undergoes a rapid decomposition with the production of light when it is heated. The picrate and the perchlorate explode violently from heat and from shock. Guanyl azide is not decomposed by boiling water. On hydrolysis with strong alkali, it yields the alkali metal salt of hydrazoic acid. It is hydrolyzed by am-moniacal silver nitrate in the cold with the formation of silver azide which remains in solution and of silver cyanamide which appears as a yellow precipitate. By treatment with acids or weak bases it is converted into 5-aminotetrazole. 

Chemical analysis of expl reaction products has been performed utilizing spectroscopic methods. A study of the thermal decompn of Tetrazene at 90° has demonstrated that substantially complete conversion to 5-aminotetra-zoie is effected (Ref 69). Spectroscopic evidence has indicated that this product is derived from both the side chain (guanyl azide) and the Tetrazole ring. Utilizing the unique-to-mercury absorption line at 2536.5a, mercury (II) concn... 

R. Bird A.J. Power. Thermal Decomposition of Tetrazene at 90°C , MRL-R-710, Australia (1978) [The authors report that Tetrazene is converted into 5-aminotetrazole in less than three days at 90°, thus losing its stab sensy property. Spectroscopic evidence indicates that the 5-aminotetrazole is derived from both the side chain (via guanyl azide) and the Tetrazole ring] 24) G.B. Franklin C.F. Parrish, Radiation Polymerized Priming Compositions , USP 4056416 (1977) CA 88, 52661 (1978) [The inventors claim that extrudable primers with good percussion sensy are prepd from Tetrazene 3.9—4.1, n-Pb Styphnate 32—42,... 

A series of 5-aminoaryltetrazoles were obtained directly from the corresponding l-aryl-5-aminotetrazoles by a one-pot sequential ring-opening, azidation, and intramolecular cyclization. 5-Alkylamino-l-aryltetrazoles are formed by a similar mechanism from 1,4-disubstituted tetrazolium salts. The influence of the aryl substituents and reaction conditions on the regioselectivity of the intramolecular cyclization of the intermediate guanyl azides was revealed <2006S1307>. 

The tendency of compounds RCN3=X to cyclize depends on the nature of X. When it is oxygen only open chain compounds are detected , and similarly for hydrazidic acids, RCNg=NNHAr, attempts to synthesize the cyclic form were failures . The latter type of compounds rearranged on treatment with acid to form semi-carbazides with retention of configuration. Guanyl azides can be isolated in open chain forms that cyclize on heating (reaction 94). 

Alkylamino- or 5-arylaminotetrazoles can be equilibrated with 1-alkyl or l-aryl-5-aminotetrazoles respectively. Lieber has shown that tiiis isomerization goes through the corresponding guanyl azides, rather than through bicyclic intermediates discussed earlier... 

The guanyl azides are intermediates of higher energy than the tetrazoles in these isomerizations. Consequently, substituents that stabilize the azides also lower the energy of activation for the ringopening of the tetrazoles, an expectation confirmed by Lieber s kinetic data. 

Carbanions can displace azide ion from carbonyl azides . For displacements at guanyl azides see section I.B and at carbamoyl azides see section I.C. 

An tmino-dcrivative of carbamoyl azides, guanyl azide can react forming 5- aminotetrazol (X) (73), a substance with explosive properties ... 

In a similar way to azidoazomethines, the corresponding azido oximes and hydrazides may be obtained (Scheme 43). The formation of cyclic tautomers seems to play only a minor role here." The stereochemical aspects of the transformation of 0-acylhydroxamoyl chlorides (33 R = "Ac) with N3 ions have been studied by Hegarty. Further systems such as the interesting pairs guanyl azides (34)/5-aminotetrazoles, are comprehensively discussed by Lwowski. ... 

Thiele [25] converted aminoguanidine with nitrous acid (b +g) to guanyl azide [26] which was saponified to sodium azide ... 

A one-pot protocol for the synthesis of 1-aryl-5-(N-aryl-N-aroylamino)-tetrazoles 247 from symmetrical diaryl carbodiimides 243 with sodium azide under phase transfer conditions in toluene at room temperature was developed by Ding and Weber. The carbodiimide 243 reacts with sodium azide to form a guanyl azide 244 which, after reaction with an aroyl chloride 245, imdergoes electrocycHzation to yield the substituted tetrazole 247 (Scheme 47). The reaction is limited to symmetrical diaryl carbodiimides. Di-aUcyl carbodiimides fail to react imder these conditions while asymmetrical diaryl carbodiimides lead to a mixture of tetrazole isomers [157]. 

Azidoformamidine (formerly guanyl azide) in a solution of a strong mineral acid... 

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