Description
Tetrazole is a class of synthetic organic heterocyclic compound containing a 5-member ring of four nitrogen atoms and one carbon atom. It appears as an odorless white to light-yellow crystalline powder. It has several pharmaceutical applications. Tetrazole compound can act as a bioisotere for the carboxylate group, angiotensin II receptor blockers such as losartan and candesartan as well as dimethyl thiazolyl diphenyl tetrazolium bromide (MTT), which can be used in MTT assay for quantifying the respiratory activity of liver cells. It can also be used in DNA assays. In addition, Tetrazole derivatives have also been used in explosives such as TNT or high performance solid rocket propellant formulations. Tetrazole can be synthesized through the reaction between anhydrous hydrazoic acid and hydrogen cyanide under pressure.
References
https://en.wikipedia.org/wiki/Tetrazole
https://pubchem.ncbi.nlm.nih.gov/compound/1H-Tetrazole#section=Information-Sources
Chemical Properties
white crystals or crystalline powder
Uses
Tetrazole is a catalyst for phosphoramidite synthesis. It is also used as an intermediate for the drug cilostazol. Cilostazol is an antiplatelet drug and a vasodilator. Tetrazole derivatives are used as antibiotics and optically active tetrazole-containing antifungal preparations of azole type was reported.
Preparation
The first tetrazole synthesis was reported in 1885.
Tetrazole Synthesis: Nano-TiCl4.SiO2 (0.1 g) was added to a mixture of benzonitrile (1 mmol), sodium azide (2 mmol) in DMF (5 mL) at reflux for 2 h. After completion of reaction (as monitored by TLC), the mixture was allowed to cool to room temperature, the catalyst was removed by filtration. Then by adding ice water and 4N HCl (5 mL) to the residue, a white solid was obtained. This was then washed with cold chloroform. This simple procedure yielded pure tetrazole with good yields.
Definition
ChEBI: 1H-tetrazole is a tetrazole tautomer where the proton is located on the 1st position. It is a tetrazole and a one-carbon compound. It is a tautomer of a 2H-tetrazole and a 5H-tetrazole.
Application
1H-Tetrazole is used as a bioisostere for the carboxylate group. It is also used as coupling reagent for preparation of polynucleotides.
General Description
Tetrazole is an odorless white to light-yellow crystalline powder. Mp:1 55-157°C. When heated to decomposition Tetrazole emits toxic oxides of nitrogen fumes. Can explode if exposed to shock or heat from friction or fire. The primary hazard is from blast effect where the entire load can explode instantaneously and not from flying projectiles and fragments.
Health Hazard
Fire may produce irritating, corrosive and/or toxic gases.
Fire Hazard
MAY EXPLODE AND THROW FRAGMENTS 1600 meters (1 MILE) OR MORE IF FIRE REACHES CARGO.
Purification Methods
Crystallise the tetrazole from EtOH and sublime it under high vacuum at ca 120o (care should be taken due to possible EXPLOSION). [Beilstein 26 H 346, 26 I 108, 26 II 196, 26 III/IV 1652.]
