5-aminotetrazole , synthesis from

Synthesis from tetrazole precursors was reported [60LA159 79JCS(P1)3085], according to which 5-aminotetrazole (388) was cyclo-condensed with 2-hydroxymethylenecyclohexanone to give tetrazolo [l,5-a]quinazoline (389) instead of the expected tetrazolo[5,l-fc] quinazoline (390). 

Table 9 Synthesis of tetrazolo[1,5-a]pyrimidines starting from 5-aminotetrazole...

The high nitrogen content and the endothermic nature of the tetrazole ring lends itself to the synthesis of energetic materials. Compounds such as -H tetrazole and 5-aminotetrazole can be used as nucleophiles to incorporate the tetrazole ring into other molecules. 5-Aminotetrazole is synthesized from the reaction of dicyandiamide with sodium azide in hydrochloric acid. 

A more extensively investigated precursor to chemically generated C atoms is diazotetrazole (6), which is easily prepared from readily available 5-aminotetrazole (7). " In this method, 7 is converted into the corresponding diazonium chloride 8, which is coated on the walls of a flask and pyrolysed in the presence of a gaseous substrate (Eq. 6). This technique has the drawback that 8 is extremely explosive and only small quantities can be prepared at a time. " However, the synthesis of 7 with a labeled carbon is quite simple, allowing convenient evaluation of the fate of the reacting carbon. " ... 

Synthesis of tetrazole compds from acid nitriles) 3)R.M.Herbst et al, JOC,16,13SM9(195l) CA 45, 6629-31(1951) (18 refs) (Prepn of various 1— alkyl—5—aminotetrazoles by the interaction of aikyicyanides with hydrazoic acid in benzene so in in the presence of a coned acid some props of... 

The synthesis of BENZYL ISOCYANIDE from benzaldehyde via reductive amination with 5-aminotetrazole followed by oxidation of the resultant amine with sodium hypobromite provides a general method for the synthesis of isocyanides. The preparation of BIS(2,2,2-TRICHLOROETHYL) AZODICARBOXYLATE makes available an alternative to dimethyl azodicarboxylate that is not only more reactive in Diels-Alder reactions but whose ester groups can be removed under neutral conditions. 

Many Tetrazole Drugs Made from 5-Aminotetrazole Analysis Synthesis... 

Scheme 46 Synthesis of 5-aminotetrazoles 242 starting from symmetrical or non-symmetrical carbodiimides 239 and TMSA (146) [111]...

Organic compounds containing pyrimidine as a core unit were known to exhibit various biological and pharmaceutical activities [108], Chun et al. [109, 110] developed a one-pot synthesis of a series of 5-aiyl-5,8-dihydrotetrazolo[l,5-a]py-rimidine-7-carboxylic acids 72 from 5-aminotetrazole, pymvic acid, and aromatic aldehydes in the presence of I2 as a catalyst. Operational simplicity, mild reaction conditions, and eco-friendly procedure made this novel protocol a promising alternative for the fusion of tetrazolopyrimidines (Scheme 10.54),... 

The method was extended to other classes of fluorinated p-dicarbonyl compounds, including p-ketoesters (Table 42, Entry 1), p-diketones (Entry 2), P-ketosulphones (Entry 3), p-ketosulphamides (Entry 4), and p-ketophosphonates (Entries 5 and 6). It should be noted that in case of some p-diketones (i.e. 1,1,1,5,5,5-hexafluoroacetylacetone), the products of principal pyrimidine synthesis were formed instead of Biginelli adducts under reaction conditions [568]. Apart from urea and thiourea, other classes of NCN binucleophiles were also introduced, including A-alkylureas (Entries 7 and 8, note different stereochemistry of the products), aminotriazoles (Entries 9 and 10), aminotetrazole (Entry 11), and 2-aminobenzimidazole (Entry 12). 

---