What Is Triazole?
Triazole is a five-membered ring compound with three nitrogen atoms and two carbon atoms, having the chemical formula C2H3N3. There are two isomeric forms: 1,2,3-triazole and 1,2,4-triazole, both exhibiting aromatic properties.
Triazole is used in pharmaceuticals, with each isomer being a component of different drugs.
Uses of Triazole
1,2,3-Triazole is an important component in the antibiotic tazobactam piperacillin for injection, used to treat conditions like complicated cystitis, pyelonephritis, pneumonia, peritonitis, sepsis, and febrile neutropenia.
Properties of Triazole
1,2,3-Triazole is crystalline, sweet-tasting, and has a melting point of 23-25 °C and a boiling point of 203 °C. It is soluble in water and ethanol. At temperatures above 500 °C in a vacuum, it decomposes, releasing nitrogen to form aziridine.
Structure of Triazole
Triazole forms a five-membered ring with two carbon and three nitrogen atoms. 1,2,3-Triazole, with adjacent nitrogen atoms, is exceptionally stable. In aqueous solution, it forms tautomers such as 2H-1,2,3-triazole.
Other Information About Triazole
1. 1,2,3-Triazole Synthesis
Substituted 1,2,3-triazole can be synthesized by Huisgen cycloaddition, a 1,3-dipolar cycloaddition reaction of an azide with an alkyne, useful in click chemistry. The Dimroth rearrangement is an example of ring-chain tautomerism involving 1,2,3-triazole.
2. Characteristics of 1,2,4-Triazole
1,2,4-Triazole is a colorless, needle-like crystal with melting and boiling points of 120 °C and 260 °C, respectively. It is planar and soluble in water and ethanol. 1,2,4-triazole undergoes both N-protonation and deprotonation in aqueous solution. It is a key component of the antifungal drug fluconazole.
3. Synthesis of 1,2,4-Triazole
Unsubstituted 1,2,4-triazole is synthesized from thiosemicarbazide and formic acid, followed by oxidation with nitric acid or hydrogen peroxide. The Einhorn-Brunner and Pellizzari reactions are also used for its synthesis.