Imidazole

Imidazole
Names
	Preferred IUPAC name 1H-Imidazole
	Other names 1,3-Diazole; Glyoxaline (archaic)
Identifiers
CAS Number	288-32-4 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	103853
ChEBI	CHEBI:16069 ;
ChEMBL	ChEMBL540 ;
ChemSpider	773 ;
DrugBank	DB03366;
ECHA InfoCard	100.005.473
EC Number	206-019-2;
Gmelin Reference	1417
KEGG	C01589 ;
PubChem CID	795;
RTECS number	NI3325000;
UNII	7GBN705NH1 ;
UN number	3263
CompTox Dashboard (EPA)	DTXSID2029616 ;
	InChI InChI=1S/C3H4N2/c1-2-5-3-4-1/h1-3H,(H,4,5) Key: RAXXELZNTBOGNW-UHFFFAOYSA-N ; InChI=1/C3H4N2/c1-2-5-3-4-1/h1-3H,(H,4,5);
	SMILES c1cnc[nH]1;
Properties
Chemical formula	C3H4N2
Molar mass	68.077 g/mol
Appearance	White or pale yellow solid
Density	1.23 g/cm3, solid
Melting point	89 to 91 °C (192 to 196 °F; 362 to 364 K)
Boiling point	256 °C (493 °F; 529 K)
Solubility in water	633 g/L
Acidity (pKa)	6.95 (for the conjugate acid)
UV-vis (λmax)	206 nm
Structure
Crystal structure	Monoclinic
Coordination geometry	Planar 5-membered ring
Dipole moment	3.61 D
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Corrosive
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H314, H360D
Precautionary statements	P263, P270, P280, P301+P310, P305+P351+P338, P308+P313
Flash point	146 °C (295 °F; 419 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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.

When fused to a pyrimidine ring, it forms a purine, which is the most widely occurring nitrogen-containing heterocycle in nature.

The name "imidazole" was coined in 1887 by the German chemist Arthur Rudolf Hantzsch (1857–1935).