1.5- Diaminotetrazole

Alternatively, cyclocondensation of 1,5-diaminotetrazole 1024 with gly-oxal and substituted glyoxals produced tetrazolo[ 1,5-6][l, 2,4]triazine 1025 (88JOC5371), which can be reduced to 7,8-dihydro derivative 1026 using Pd/C as a hydrogenating catalyst, but NaBH4 gave 5,6,7,8-tetrahydro derivative 1027. 

Other cyclizations to give tetrazolo[l,5-7][l,2,4]triazines published in recent years basically follow the established procedures discussed earlier in CHEC-II(1996) < 1996CHEC-II(8)499> and belong to two categories (1) reaction of 1,5-diaminotetrazole 42 with ct-dioxo reagents, and (2) reaction of a 3-hydrazino[l,2,4]triazine derivative with nitrous acid. 

The bis-nitramine (155) has been prepared from the reaction of 1,5-diaminotetrazole (152) with glyoxal, followed by reduction of the resulting fused heterocycle (153) with sodium borohydride and subsequent A-nitration of the piperazine nitrogens of (154). ... 

On the basis of the literature data [53,56,57] of the synthesis of dihydrodiazepine and dihydrotriazepine derivatives by chalcone reaction with diamines such as 1,3-dimethyl-5,6-diaminouracil and diaminotetrazole, the suggested structure of the products of these interactions was later proved to be erroneous [61, 62,63]. Analysis of the reaction paths actually observed under such conditions is presented in Sect. 4.5. 

The formation of pyrazoline derivatives 175 (but not dihydrotetrazolotria-zepines 173, as assumed earlier [53]) is brought about by the condensation of chalcones with diaminotetrazole 172 [128,129]. The structure of the compounds 175 is convincingly verified using X-rays. The mechanism of their formation implies a Dimrothe rearrangement for either the initial diamine or for one of the cyclocondensation intermediates (Scheme 4.51). 

The thermal decomposition of 5-aminotetrazole, l-methyl-5-aminotetrazole, 1,5-diaminotetrazole, poly-l-vinyl-5-aminotetrazole, and the sodium salt of 5-aminotetrazole have been studies by thermogravimetry, thermal volumetric analysis (DSC, DTA, TVA), and EGA (Tables 19 and 20) <2002THE233>. 

The peroxidase-catalyzed oxidation of 2,2 -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), o-phenylene-diamine (PDA), and 3,3, 5,5 -tetramethylbenzidine (TMB) was found to be activated by tetrazole 2 and 5-aminote-trazole and weakly inhibited by 1,5-diaminotetrazole 33 <2004MI283>. Bhattacharya and Vemula studied the effect of heteroatom insertion in the side chain of 5-alkyl-177-tetrazoles on their properties as catalysts for ester hydrolysis at neutral pH <2005JOC9677>. l-(2-Iodophenyl)-177-tetrazole was successfully used in Heck reactions to give the cross-coupled products in excellent yield <2004TL4113>. 

Fig. 9.8 Two synthetic routes for the synthesis of aminotetrazole (AT, a) and the synthetic route for diaminotetrazole (DAT, b).

The synthesis of these compounds is relatively facile using trinitroethanol and the corresponding amines, while for the synthesis of TTD diaminotetrazole, BTTD TTD and for BTAT, diamino-tetrazine was used (Fig. 9.18). At pH values above 6, trinitroethanol behaves as an acid, so that for the Mannich reaction shown in Figure 9.18, two different mechanisms can be discussed. 

A general method of synthesizing 1,5-diaminotetrazoles was first worked out by Stolle (31JPR209) and was then modified by Ukrainian chemists (84KGS1683). This involves the action of sodium azide and lead dioxide on thiosemicarbazide or on its N-substituted derivatives [Eq. (56)]. Presumably, the intermediate in this reaction is carbodiimide 235, which adds the azide ion before cyclization. The use of thiocarbohydrazide in-... 

Tetrazole and its 5-substituted derivatives are aminated by HOSA in aqueous sodium carbonate to afford a mixture of 1- and 2-aminotetra-zoles in yields of 40-50% [Eq. (58)] (69CJC3677). The amination of 5-aminotetrazoIe is less successful, and the total yield of 1,5- and 2,5-diaminotetrazoles is not greater than 13%. Usually, the yield of 1-aminotet-razole is 1.5-2 times greater than that of the 2-isomer. An exception is 5-phenyltetrazole, which presents the opposite result. 

Heating imines 336 derived from 1,5-diaminotetrazole in DMSO provided hydrazones 337 via Dimroth rearrangement. The reaction was greatly favored due to the electron-withdrawing groups attached to the imine carbon atom (90CB1575) (Scheme 103). 

Because of the difficult accessibility of 1,5-diaminotetrazole (DAT, Fig. 8), only few synthetic methods for its preparation have been described in the literature. This compound, as all aminotetrazoles, has the highest content of nitrogen among organic substances (about 84%) and due to the aromaticity, it exhibits a relatively high thermal stability. 

A milestone in the synthesis of DAT was described by Raap [36] who reacted the sodium salt of 5-aminotetrazole with hydroxylamine-O-sulfonic acid and obtained a mixture of 1,5-diaminotetrazole (1,5-DAT) and 2,5-di-aminotetrazole (2,5-DAT), where the first constitutes 8.5% of the reaction yield (Fig. 9). 

Fig. 9.6 Crystals of 1,5-diaminotetrazole ferrous perchlorate complex [50]. Reprinted by permission of the Department of the Navy employees, M. Bichay,...

Very little is published about the physical and chemical properties of these 1,5-diaminotetrazole complexes. Crystals of the 1,5-diaminotetrazole ferrous perchlorate complex are shown in Fig. 9.6. 

Sensitivity values of cupric and ferrous perchlorate complexes of 1,5-diaminotetrazole are compared to LS in Table 9.6 and the performance data measured by plate dent test and compared to LA are summarized in Table 9.7. 

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