Benzimidazole: Difference between revisions
→Applications: expanded section |
Cymru.lass (talk | contribs) Fix order Tags: Reverted Mobile edit Mobile web edit Advanced mobile edit |
||
| Line 1: | Line 1: | ||
| ⚫ | |||
{{chembox |
|||
| Watchedfields = changed |
| Watchedfields = changed |
||
| verifiedrevid = 443415791 |
| verifiedrevid = 443415791 |
||
| Line 56: | Line 56: | ||
| AutoignitionPt = |
| AutoignitionPt = |
||
}} |
}} |
||
}} |
|||
| ⚫ | |||
'''Benzimidazole''' is a [[heterocyclic]] [[aromatic]] [[organic compound]]. This bicyclic compound may be viewed as fused rings of the aromatic compounds [[benzene]] and [[imidazole]]. It is a colorless solid. |
'''Benzimidazole''' is a [[heterocyclic]] [[aromatic]] [[organic compound]]. This bicyclic compound may be viewed as fused rings of the aromatic compounds [[benzene]] and [[imidazole]]. It is a colorless solid. |
||
Revision as of 15:50, 7 January 2023
Benzimidazole is a heterocyclic aromatic organic compound. This bicyclic compound may be viewed as fused rings of the aromatic compounds benzene and imidazole. It is a colorless solid.
Preparation
Benzimidazole is produced by condensation of o-phenylenediamine with formic acid,[1] or the equivalent trimethyl orthoformate:
- C6H4(NH2)2 + HC(OCH3)3 → C6H4N(NH)CH + 3 CH3OH
2-substituted derivatives are obtained when the condensation is conducted with aldehydes in place of formic acid, followed by oxidation.[2]
Reactions
Benzimidazole is a base:
- C6H4N(NH)CH + H+ → [C6H4(NH)2CH]+
It can also be deprotonated with stronger bases:
- C6H4N(NH)CH + LiH → Li [C6H4N2CH] + H2
The imine can be alkylated and also serves as a ligand in coordination chemistry. The most prominent benzimidazole complex features N-ribosyl-dimethylbenzimidazole as found in vitamin B12.[3]
N,N'-Dialkylbenzimidazolium salts are precursors to certain N-heterocyclic carbenes.[4][5]
Applications
Benzimidazole derivatives are among the most frequently used ring systems for small molecule drugs listed by the United States Food and Drug Administration.[6] Many pharmaceutical agents belong to the benzimidazole class of compounds. For example:
- 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.
- Other notable pharmaceutical agents which contain a benzimidazole group include abemaciclib, bendamustine, dabigatran, daridorexant, and glasdegib.
In printed circuit board manufacturing, benzimidazole can be used as an organic solderability preservative.[citation needed]
Several dyes are derived from benzimidazoles.[7]
See also
- Benzimidazoline
- Polybenzimidazole, a high performance fiber
References
- ^ E. C. Wagner and W. H. Millett (1943). "Benzimidazole". Organic Syntheses; Collected Volumes, vol. 2, p. 65..
- ^ Robert A. Smiley "Phenylene- and Toluenediamines" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_405
- ^ H. A. Barker; R. D. Smyth; H. Weissbach; J. I. Toohey; J. N. Ladd & B. E. Volcani (February 1, 1960). "Isolation and Properties of Crystalline Cobamide Coenzymes Containing Benzimidazole or 5,6-Dimethylbenzimidazole". Journal of Biological Chemistry. 235 (2): 480–488. doi:10.1016/S0021-9258(18)69550-X. PMID 13796809.
- ^ R. Jackstell; A. Frisch; M. Beller; D. Rottger; M. Malaun; B. Bildstein (2002). "Efficient telomerization of 1,3-butadiene with alcohols in the presence of in situ generated palladium(0)carbene complexes". Journal of Molecular Catalysis A: Chemical. 185 (1–2): 105–112. doi:10.1016/S1381-1169(02)00068-7.
- ^ H. V. Huynh; J. H. H. Ho; T. C. Neo; L. L. Koh (2005). "Solvent-controlled selective synthesis of a trans-configured benzimidazoline-2-ylidene palladium(II) complex and investigations of its Heck-type catalytic activity". Journal of Organometallic Chemistry. 690 (16): 3854–3860. doi:10.1016/j.jorganchem.2005.04.053.
- ^ Taylor, R. D.; MacCoss, M.; Lawson, A. D. G. J Med Chem 2014, 57, 5845.>
- ^ Horst Berneth "Methine Dyes and Pigments" in Ullmann's Encyclopedia of Industrial Chemistry, 2008, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_487.pub2
Further reading
- Grimmett, M. R. (1997). Imidazole and benzimidazole synthesis. Boston: Academic Press. ISBN 0-12-303190-7.
| Authority control databases: National |
|---|
