Benzofuran

Benzofuran
Names
	Preferred IUPAC name 1-Benzofuran
	Other names Benzofuran; Coumarone; Benzo[b]furan
Identifiers
CAS Number	271-89-6 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	107704
ChEBI	CHEBI:35260 ;
ChEMBL	ChEMBL363614 ;
ChemSpider	8868 ;
DrugBank	DB04179 ;
ECHA InfoCard	100.005.439
EC Number	205-982-6;
Gmelin Reference	260881
KEGG	C14512 ;
PubChem CID	9223;
RTECS number	DF6423800;
UNII	LK6946W774 ;
UN number	1993
CompTox Dashboard (EPA)	DTXSID6020141 ;
	InChI InChI=1S/C8H6O/c1-2-4-8-7(3-1)5-6-9-8/h1-6H Key: IANQTJSKSUMEQM-UHFFFAOYSA-N ; InChI=1/C8H6O/c1-2-4-8-7(3-1)5-6-9-8/h1-6H Key: IANQTJSKSUMEQM-UHFFFAOYAU;
	SMILES o2c1ccccc1cc2;
Properties
Chemical formula	C8H6O
Molar mass	118.135 g·mol−1
Melting point	−18 °C (0 °F; 255 K)
Boiling point	173 °C (343 °F; 446 K)
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H226, H351, H412
Precautionary statements	P201, P202, P210, P233, P240, P241, P242, P243, P273, P280, P281, P303+P361+P353, P308+P313, P370+P378, P403+P235, P405, P501
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	500 mg/kg (mice).
Related compounds
Related compounds	Benzothiophene, Indole, Indene, 2-Cumaranone
	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

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.

There are benzofuran based herbicides: ethofumesate and benfuresate. Several psychoactive drugs such as 5-MAPB and 6-APB are also derived from benzofuran.

Production

Benzofuran is extracted from coal tar. It is also obtained by dehydrogenation of 2-ethylphenol.

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.

Perkin rearrangement, where a coumarin is reacted with a hydroxide:

Diels–Alder reaction^{[clarification needed]} of nitro vinyl furans with various dienophiles:

Cycloisomerization of alkyne ortho-substituted phenols:

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

References

1 2 "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 218. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
1 2 Collin, G.; Höke, H. (2007). "Benzofurans". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.l03_l01. ISBN 978-3527306732.
↑ "Classification of herbicides". bcpcpesticidecompendium.org. Retrieved 21 August 2025.
↑ Burgstahler, A. W.; Worden, L. R. (1966). "Coumarone" (PDF). Organic Syntheses. 46: 28; Collected Volumes, vol. 5, p. 251.
↑ Perkin, W. H. (1870). "XXIX. On some New Bromine Derivatives of Coumarin". Journal of the Chemical Society. 23: 368–371. doi:10.1039/JS8702300368.
↑ Perkin, W. H. (1871). "IV. On some New Derivatives of Coumarin". Journal of the Chemical Society. 24: 37–55. doi:10.1039/JS8712400037.
↑ Bowden, K.; Battah, S. (1998). "Reactions of Carbonyl Compounds in Basic Solutions. Part 32. The Perkin Rearrangement". Journal of the Chemical Society, Perkin Transactions 2. 1998 (7): 1603–1606. doi:10.1039/a801538d.
↑ Kusurkar, R. S.; Bhosale, D. K. (1990). "Novel Synthesis of Benzosubstituted Benzofurans Via Diels-Alder Reaction". Synthetic Communications. 20 (1): 101–109. doi:10.1080/00397919008054620.
↑ Fürstner, Alois & Davies, Paul (2005). "Heterocycles by PtCl2-Catalyzed Intramolecular Carboalkoxylation or Carboamination of Alkynes". Journal of the American Chemical Society. 127 (43): 15024–15025. doi:10.1021/ja055659p. hdl:11858/00-001M-0000-0025-AA5A-1. PMID 16248631.

[iupac2013-1] 1 2 "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 218. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.

[Ullmann-2] 1 2 Collin, G.; Höke, H. (2007). "Benzofurans". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.l03_l01. ISBN 978-3527306732.

[3] "Classification of herbicides". bcpcpesticidecompendium.org. Retrieved 21 August 2025.

[4] Burgstahler, A. W.; Worden, L. R. (1966). "Coumarone" (PDF). Organic Syntheses. 46: 28; Collected Volumes, vol. 5, p. 251.

[5] Perkin, W. H. (1870). "XXIX. On some New Bromine Derivatives of Coumarin". Journal of the Chemical Society. 23: 368–371. doi:10.1039/JS8702300368.

[6] Perkin, W. H. (1871). "IV. On some New Derivatives of Coumarin". Journal of the Chemical Society. 24: 37–55. doi:10.1039/JS8712400037.

[7] Bowden, K.; Battah, S. (1998). "Reactions of Carbonyl Compounds in Basic Solutions. Part 32. The Perkin Rearrangement". Journal of the Chemical Society, Perkin Transactions 2. 1998 (7): 1603–1606. doi:10.1039/a801538d.

[8] Kusurkar, R. S.; Bhosale, D. K. (1990). "Novel Synthesis of Benzosubstituted Benzofurans Via Diels-Alder Reaction". Synthetic Communications. 20 (1): 101–109. doi:10.1080/00397919008054620.

[9] Fürstner, Alois & Davies, Paul (2005). "Heterocycles by PtCl2-Catalyzed Intramolecular Carboalkoxylation or Carboamination of Alkynes". Journal of the American Chemical Society. 127 (43): 15024–15025. doi:10.1021/ja055659p. hdl:11858/00-001M-0000-0025-AA5A-1. PMID 16248631.

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