5-Hydrazino-tetrazole

Hydrazino-tetrazole (Tetrazyl-5-hydrazine) ([Tetrazolyl-(5)] -hydrazin, Tetrazolonhydrazon in German) ... 

BNCP and its analogs are sensitive to light and may be detonated by laser pulses. Initial studies [43] report use of a variety of laser sources at 800 and 1,060 nm, with later activities, studying the sensitivity of pressed powders to a single pulse, using solid state neodymium laser (1,060 nm, 1.5 J, 2 ms, beam diameter 1 mm) [44]. BNCP analogs are evaluated as alternatives to substances such as hydrazino tetrazole mercury(II) perchlorate which is probably the most sensitive substance with respect to laser pulses (initiation time around 30 ns at 1.10 " J) [39]. 

The presence of a 5-oxo group in the 1,2,4-triazines, as in 3-hydrazino-2,5-dihydro-5-oxo[l,2,4]triazines, does not alter the direction of cycliza-tion by the action of nitrous acid. The initial products are azido compounds 1016, which can cyclize spontaneously to tetrazolo[l,5-b][l,2,4]triazines 1017 (77JHC1221, 77JOC1866) rather than the previously reported isomeric structure. On the other hand, when the cyclization onto N-2 is impossible, as in derivative 1018, the azidotetrazolo equilibrium 1018 1019 exists (76JOC2860 77JOC1866). It exists in the solid state at least as the tetrazole derivative (Scheme 190). 

Aryl-tetrazole liefern mit 2-Benzyliden-l-chlorcarbonyl-l-phenyl-hydrazin 5-Aryl-2-(2-benzyliden-1 -phenyl-hydrazino)- , 3,4-oxadiazole547. 

Azido-2H-l,2,4-triazin-3-ones (56a) also cyclize to give the tetrazolo[5,l-d]-[l,2,4]triazin-3-ones (56b) (71RRC135, 71RRC311). Nitrosation of 3-amino-6-hydrazino-l,2,4-triazin-5-one (57) affords a compound which exhibits an intense absorption at 2140cm-1, showing that the 6-azido tautomer (58a) was isolated. When this compound was stirred for a few minutes in a polar solvent it quantitatively formed the tetrazole tautomer (58b) (79JHC555). 

One of the classical methods for the generation of imidoyl azides as precursors to mono- and disubstituted tetrazoles is based on reactions of amidrazoles with sodium nitrite. This procedure developed by Kaufmann et al. in the middle of thel960s <2004SOS(13)861> has found an extension and advancement in recent studies. By this method, 5-hydrazino-3-methyl-l-phenyl-l//-pyrazolo[4,3-< ][l,2,4]triazine 503 through a cyclic imidoyl azide 504 was converted into 5-phcnyl-l //-pyra/olo[4,3-<,]tetrazolo[4,5- tria/inc 505 (Scheme 64) <2005JCX151>. 

Ref 2,p 213), stated that this compd can be prepd by treating thiocarbohydrazide with PbO and NaN, but they did not describe the method. They did, however, give the method of prepn of l-amino- -hydrazino-vic-tetrazole hydrochloride, CHjN, -HCl, It yel crys which vigorously decompd with evoln of gas ca 171° easily sol in w, giving a strongly acidic soln. Its method of prepn consisted of heating 1-di ben zalamino-5 hydrazinotetra-zole with 20% hydrochloric acid... 

Azido-2,2-dimethyl-8-oxo-E16b, 723 (CH - C-N3) lH-Pyrazol 4-Nitro-3(5)-piperidino-E8b, 598 (N02 - NR2) Pyrimidin 5-Ethoxycarbonyl-2-hydrazino-4-methyl- El 6a, 771 (SR - NH-NH2) lH-Tetrazol l-(l-Carboxy-2-methyl-... 

Quinolin 2,4-Bis-[hydrazino]- E16a, 703 (Cl - NH-NH2) lH-Tetrazol 5-Dimethylamino-l-phenyl- E8d, 689... 

Nonan, 5-Butyl-4,5-diazido- E19a, 513 (En N3-C-C-N3) lH-Tetrazol l-Cydohexyl-5-[l-methyl-1 -(1,2,2-trimethyl-hydrazino)-ethyl]- E8d, 717 (HUC6 — NC + HNj/Aceton R2N-NH-R)... 

When 5-chloro-l-phenyltetrazoJe (289 X=N) was heated with five equivalents of hydrazine hydrate in methanol, it yielded the tetrazole 291 (X=N) through rearrangement of the 5-hydrazino intermediate (88BSB543 89BSB343). 

Alkyl-3-chloro-4-cyano-l -hydrazino-5,6,7,8-tetrahydro-2,7-naphthal-pyridines react with nitrous acid to form the azides, which are in equilibrium with the tetrazoles (Scheme 29). Unlike other examples of this equilibrium, these appear to exist primarily as the azides. As such, they have a number of handles (such as the chloride and cyano), which allow them to be transformed into other fused systems including two new tet-racycles. Reaction of the azides with amines proceeded via nucleophilic substitution of the chloride at C-3.With more forcing conditions of higher temperature and an excess of the amine, the azido can be replaced by nucleophilic substitution, which is rare for these compounds. When the azides were treated with hydrazine, a pyrazole-fused system is formed.With ethyl mercaptoacetate, a thiazole-fused system is formed (14T8648). 

Fig. 9. Structures of phenylalanine (1 ) and of phenylalanine analogs discussed in the text. ( ), 5-(l-amino-2-phenylethyl)tetrazole ( ), (1-amino-2-phenylethy1) phosphonic acid ( ), (l-amino-2-phenylethyl)phosphonous acid ( ), a-aminooxy-8-phenylpropionic acid ( ), a-hydrazino-6-phenylpropionic acid (7 ), 3-methylene-phenylalanine (S), (1,4-cyclohexadienyl)-alanine ( ), o-carboranylalanine (10), adamantylalanine.

Hydrazino-l//-tetrazole can also be used as a starting material for 5-azidotetrazole preparation. Preparation may be done by treating sodium nitrite and hydrochloric acid with 5-hydrazino-l//-tetrazole in an aqueous environment [77, 85, 86] ... 

Lin, Q.H., Li, U.C., Qi, C. etal. (2013) Nitrogen-rich salts based on 5-hydrazino-lH-tetrazole a new family of high-density energetic materials. Journal of Materials... 

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