Benzimidazole

Benzimidazole

Names
Preferred IUPAC name 1H-1,3-Benzimidazole
Other names 1H-Benzo[d]imidazole
Identifiers
CAS Number	51-17-2 Y
3D model (JSmol)	Interactive image
Beilstein Reference	109682
ChEBI	CHEBI:41275 Y
ChEMBL	ChEMBL306226 Y
ChemSpider	5593 Y
DrugBank	DB02962
ECHA InfoCard	100.000.075
EC Number	200-081-4
Gmelin Reference	3106
KEGG	C02009 Y
PubChem CID	5798
UNII	E24GX49LD8 Y
CompTox Dashboard (EPA)	DTXSID8024573
SMILES c1ccc2c(c1)[nH]cn2
Properties
Chemical formula	C7H6N2
Molar mass	118.14 g·mol−1
Melting point	170 to 172 °C (338 to 342 °F; 443 to 445 K)
Acidity (pKa)	12.8 (for benzimidazole) and 5.6 (for the conjugate acid)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Benzimidazole is an aromatic organic compound, and benzimidazoles are (always) heterocyclic. (Heterocyclic aromatic organic compound is how Benzimidazole is often described. A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s).)

Benzimidazole is used to produce drugs, plastics and dyes.

Examples and uses

Benomyl is a fungicide with a benzimidazole core

The chemical compound can be found in

• Angiotensin II receptor blockers such as azilsartan, candesartan, and telmisartan.
• Anthelmintic agents such as albendazole, ciclobendazole, fenbendazole, flubendazole, mebendazole, oxfendazole, oxibendazole, triclabendazole, and thiabendazole.
• Antihistamines such as astemizole, bilastine, clemizole, emedastine, mizolastine, and oxatomide.
• Benzimidazole fungicides such as benomyl, carbendazim, fuberidazole, and thiabendazole.
• Benzimidazole opioids such as bezitramide, brorphine, clonitazene, etodesnitazene, etonitazene, etonitazepipne, etonitazepyne, isotonitazene, metodesnitazene, and metonitazene.
• Proton-pump inhibitors such as dexlansoprazole, esomeprazole, ilaprazole, lansoprazole, omeprazole, pantoprazole, rabeprazole, and tenatoprazole.
• Typical antipsychotics such as benperidol, clopimozide, droperidol, neflumozide, and oxiperomide, and pimozide.
• Benzimidazole can also be found in abemaciclib, bendamustine, dabigatran, daridorexant, and glasdegib.

When printed circuit boards are manufactured (or made), benzimidazole can be used as an organic solderability preservative. (When that kind of preservative gets used, it can protect copper contacts (for years), until the contact gets soldered.)