:Benzofuran
{{short description|Heterocyclic compound consisting of fused benzene and furan rings}}
{{about|the heterocyclic chemical compound|its purportedly recreational derivative drugs|Benzofury (disambiguation)}}
{{Use dmy dates|date=March 2024}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 443666007
| Name = Benzofuran
| PIN = 1-Benzofuran{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The Royal Society of Chemistry | date = 2014 | location = Cambridge | page = 218 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4| chapter = Front Matter }}
| OtherNames = Benzofuran
Coumarone
Benzo[b]furan
| ImageFile = Benzofuran 2D numbered.svg
| ImageClass = skin-invert-image
| ImageSize = 160
| ImageAlt = Skeletal formula with numbering convention
| ImageFileL1 = Benzofuran-3D-balls.png
| ImageSizeL1 = 140
| ImageAltL1 = Ball-and-stick model
| ImageFileR1 = Benzofuran-3D-spacefill.png
| ImageClassR1 = bg-transparent
| ImageSizeR1 = 120
| ImageAltR1 = Space-filling model
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8868
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 363614
| PubChem = 9223
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C14512
| InChI = 1/C8H6O/c1-2-4-8-7(3-1)5-6-9-8/h1-6H
| InChIKey = IANQTJSKSUMEQM-UHFFFAOYAU
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C8H6O/c1-2-4-8-7(3-1)5-6-9-8/h1-6H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = IANQTJSKSUMEQM-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 271-89-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = LK6946W774
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 35260
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB04179
| EC_number = 205-982-6
| RTECS = DF6423800
| UNNumber = 1993
| Beilstein = 107704
| Gmelin = 260881
| SMILES = o2c1ccccc1cc2
}}
| Section2 = {{Chembox Properties
|C=8|H=6|O=1
| MeltingPtC = −18
| BoilingPtC = 173
}}
| Section4 = {{Chembox Hazards
| GHSPictograms = {{GHS02}}{{GHS08}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|226|351|412}}
| PPhrases = {{P-phrases|201|202|210|233|240|241|242|243|273|280|281|303+361+353|308+313|370+378|403+235|405|501}}
}}
| Section8 = {{Chembox Related
| OtherCompounds = Benzothiophene, Indole, Indene, 2-Cumaranone
}}
}}
Benzofuran is the heterocyclic compound consisting of fused benzene and furan rings. This colourless liquid is a component of coal tar. Benzofuran is the structural nucleus (parent compound) of many related compounds with more complex structures. For example, psoralen is a benzofuran derivative that occurs in several plants.
Production
Benzofuran is extracted from coal tar. It is also obtained by dehydrogenation of 2-ethylphenol.{{cite encyclopedia |author1=Collin, G. |author2=Höke, H. | encyclopedia = Ullmann's Encyclopedia of Industrial Chemistry | year = 2007 | publisher = Wiley-VCH | location = Weinheim | doi = 10.1002/14356007.l03_l01|isbn=978-3527306732 |chapter=Benzofurans }}
=Laboratory methods=
Benzofurans can be prepared by various methods in the laboratory. Notable examples include:
- O-alkylation of salicylaldehyde with chloroacetic acid followed by dehydration (cyclication) of the resulting ether and decarboxylation.{{OrgSynth | author = Burgstahler, A. W. |author2=Worden, L. R. | title = Coumarone | year = 1966 | volume = 46 | pages = 28 | collvol = 5 | collvolpages = 251 | prep = cv5p0251 | url = http://www.orgsyn.org/Content/pdfs/procedures/cv5p0251.pdf}}
- Perkin rearrangement, where a coumarin is reacted with a hydroxide:{{cite journal | author = Perkin, W. H. | authorlink = W. H. Perkin | title = XXIX. On some New Bromine Derivatives of Coumarin | journal = Journal of the Chemical Society | year = 1870 | volume = 23 | pages = 368–371 | doi = 10.1039/JS8702300368| url = https://zenodo.org/record/2126035 }}{{cite journal | author = Perkin, W. H. | authorlink = W. H. Perkin | title = IV. On some New Derivatives of Coumarin | journal = Journal of the Chemical Society | year = 1871 | volume = 24 | pages = 37–55 | doi = 10.1039/JS8712400037| url = https://zenodo.org/record/1848365 }}{{cite journal |author1=Bowden, K. |author2=Battah, S. | title = Reactions of Carbonyl Compounds in Basic Solutions. Part 32. The Perkin Rearrangement | journal = Journal of the Chemical Society, Perkin Transactions 2 | year = 1998 | volume = 1998 | issue = 7 | pages = 1603–1606 | doi = 10.1039/a801538d}}
:Image:Perkin rearrangement.svg
- Diels–Alder reaction{{clarify|reason=D–A itself does not support the loss of nitro|date=September 2022}} of nitro vinyl furans with various dienophiles:{{cite journal|last=Kusurkar|first=R. S.|author2=Bhosale, D. K.|title=Novel Synthesis of Benzosubstituted Benzofurans Via Diels-Alder Reaction|journal=Synthetic Communications|date=1990|volume=20|issue=1|pages=101–109|doi=10.1080/00397919008054620}}
:Image:Benzofuran synthesis via a Diels-Alder reaction on vinyl furans.png
- Cycloisomerization of alkyne ortho-substituted phenols:{{cite journal|author1=Fürstner, Alois |author2=Davies, Paul |name-list-style=amp |title=Heterocycles by PtCl2-Catalyzed Intramolecular Carboalkoxylation or Carboamination of Alkynes|journal=Journal of the American Chemical Society|date=2005|volume=127|issue=43|pages=15024–15025|doi=10.1021/ja055659p|pmid=16248631 |hdl=11858/00-001M-0000-0025-AA5A-1 |hdl-access=free}}
Related compounds
- Substituted benzofurans
- Dibenzofuran, an analog with a second fused benzene ring.
- Furan, an analog without the fused benzene ring.
- Indole, an analog with a nitrogen instead of the oxygen atom.
- Benzothiophene, an analog with a sulfur instead of the oxygen atom.
- Isobenzofuran, the isomer with oxygen in the adjacent position.
- Aurone
- Thunberginol F