Tetrazole

Tetrazole

Names
IUPAC name 1H-Tetrazole
Identifiers
CAS Number	288-94-8 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:33193 Y
ChemSpider	60842 Y
ECHA InfoCard	100.005.477
PubChem	67519
InChI InChI=1S/CH2N4/c1-2-4-5-3-1/h1H,(H,2,3,4,5) Y Key: KJUGUADJHNHALS-UHFFFAOYSA-N Y InChI=1/CH2N4/c1-2-4-5-3-1/h1H,(H,2,3,4,5) Key: KJUGUADJHNHALS-UHFFFAOYAI InChI=1S/CH2N4/c1-2-4-5-3-1/h1H,(H,2,3,4,5) Key: KJUGUADJHNHALS-UHFFFAOYSA-N
SMILES n1nnnc1
Properties
Chemical formula	CH2N4
Molar mass	70.05 g/mol
Density	1.477 g/mL
Melting point	157 to 158 °C (315 to 316 °F; 430 to 431 K)
Boiling point	220 ± 23 °C (428 ± 41 °F; 493 ± 23 K)
Acidity (pKa)	4.90
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Tetrazoles are a class of synthetic organic heterocyclic compound, consisting of a 5-member ring of four nitrogen atoms and one carbon atom. The simplest is tetrazole itself, CH₂N₄. They are unknown in nature.

Tetrazole was first prepared by the reaction of anhydrous hydrazoic acid and hydrogen cyanide under pressure. Treatment of organic nitriles with sodium azide in the presence of iodine or silica-supported sodium bisulfate as a heterogeneous catalyst enables an advantageous synthesis of 5-substituted 1H-tetrazoles. 2-Aryl-2H-tetrazoles are synthesized by a [3+2] cycloaddition reaction between an aryl diazonium and trimethylsilyldiazomethane.

There are several pharmaceutical agents which are tetrazoles. The tetrazole ring can act as a bioisostere for the carboxylate group. Angiotensin II receptor blockers - such as losartan and candesartan, often are tetrazoles. A well-known tetrazole is dimethyl thiazolyl diphenyl tetrazolium bromide (MTT). This tetrazole is used in the MTT assay to quantify the respiratory activity of live cells culture, although it generally kills the cells in the process. Some tetrazoles can also be used in DNA assays.

Some tetrazole derivatives with high energy have been investigated as high performance explosives as a replacement for TNT and also for use in high performance solid rocket propellant formulations.