Imidazole (ImH) is an organic compound with the formula (CH)3(NH)N. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. It can be classified as a heterocycle, specifically as a diazole.
Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. This ring system is present in important biological building blocks, such as histidine and the related hormone histamine. Many drugs contain an imidazole ring, such as certain antifungal drugs, the nitroimidazole series of antibiotics, and the sedative midazolam.[5][6][7][8][9]
When fused to a pyrimidine ring, it forms a purine, which is the most widely occurring nitrogen-containing heterocycle in nature.[10]
^Walba, H.; Isensee, R. W. (1961). "Acidity constants of some arylimidazoles and their cations". J. Org. Chem. 26 (8): 2789–2791. doi:10.1021/jo01066a039.
^"Imidazole". molekula.com. Molekula Group. Archived from the original on 2018-10-19. Retrieved 2018-10-19.
^"Imidazole". pubchem.ncbi.nlm.nih.gov. Archived from the original on 10 May 2023. Retrieved 17 February 2024.
^Hantzsch, A. and Weber, J. H. (1887) "Ueber Verbindungen des Thiazols (Pyridins der Thiophenreihe)"Archived 2020-05-30 at the Wayback Machine (On compounds of thiazole (pyridines of the thiophene series), Berichte der deutschen chemischen Gesellschaft, 20 : 3118–3132, see p. 3119. See also: Hantzsch, A. (1888) "Allegemeine Bemerkungen über Azole"Archived 2020-05-30 at the Wayback Machine (General observations about azoles), Annalen der Chemie, 249 : 1–6. Hantzsch proposed a reform of the nomenclature of azole compounds, including a proposal to call the heterocyclic ring C3H3(NH)N "imidazole"; see pp. 2 and 4.