288-94-8

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.

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.]

General Description

Tetrazole is a heterocyclic compound with the molecular formula CH2N4, existing primarily in the 1H-tautomeric form in the gas phase, as confirmed by thermodynamic studies. It exhibits a reversible solid-to-solid transition around 230–245 K and has a fusion temperature of 430 K with an enthalpy of fusion of 18.0 kJ·mol-1. The sublimation enthalpy of crystalline tetrazole is approximately 88.25 kJ·mol-1 at 350 K, and its thermodynamic properties have been extensively characterized in both solid and gaseous states. Additionally, tetrazole serves as a versatile synthetic intermediate, functioning as an efficient leaving group in organic reactions, such as the microwave-assisted synthesis of substituted pyrimidines. It also plays a role in coordination chemistry, forming complexes with transition metals like iron(II) in spin-crossover systems. Furthermore, tetrazole derivatives, such as sodium 5-chlorotetrazolate, can be synthesized via chlorination, demonstrating distinct thermal decomposition behaviors compared to their parent compounds.

Application

1H-Tetrazole is used as a bioisostere for the carboxylate group. It is also used as coupling reagent for preparation of polynucleotides.

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.