Furan

Furan
Names
	Preferred IUPAC name Furan
	Systematic IUPAC name 1,4-Epoxybuta-1,3-diene; 1-Oxacyclopenta-2,4-diene
	Other names Oxole; Oxa[5]annulene; 1,4-Epoxy-1,3-butadiene; 5-Oxacyclopenta-1,3-diene; 5-Oxacyclo-1,3-pentadiene; Furfuran; Divinylene oxide
Identifiers
CAS Number	110-00-9 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	103221
ChEBI	CHEBI:35559 ;
ChEMBL	ChEMBL278980 ;
ChemSpider	7738 ;
ECHA InfoCard	100.003.390
EC Number	203-727-3;
Gmelin Reference	25716
KEGG	C14275 ;
PubChem CID	8029;
RTECS number	LT8524000;
UNII	UC0XV6A8N9 ;
UN number	2389
CompTox Dashboard (EPA)	DTXSID6020646 ;
	InChI InChI=1S/C4H4O/c1-2-4-5-3-1/h1-4H Key: YLQBMQCUIZJEEH-UHFFFAOYSA-N ; InChI=1/C4H4O/c1-2-4-5-3-1/h1-4H Key: YLQBMQCUIZJEEH-UHFFFAOYAC;
	SMILES c1ccoc1;
Properties
Chemical formula	C4H4O
Molar mass	68.075 g·mol−1
Appearance	Colorless, volatile liquid
Density	0.936 g/mL
Melting point	−85.6 °C (−122.1 °F; 187.6 K)
Boiling point	31.3 °C (88.3 °F; 304.4 K)
Magnetic susceptibility (χ)	−43.09·10−6 cm3/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H224, H302, H315, H332, H341, H350, H373, H412
Precautionary statements	P201, P202, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P281, P301+P312, P302+P352, P303+P361+P353, P304+P312, P304+P340, P308+P313, P312, P314, P321, P330, P332+P313, P362, P370+P378, P403+P235, P405, P501
NFPA 704 (fire diamond)	3 4 1
Flash point	−36 °C (−33 °F; 237 K)
Autoignition; temperature	390 °C (734 °F; 663 K)
Explosive limits	Lower: 2.3%; Upper: 14.3% at 20 °C
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	> 2 g/kg (rat)
Safety data sheet (SDS)	Pennakem
Related compounds
Related heterocycles	Pyrrole; Thiophene
Related compounds	Tetrahydrofuran (THF); 2,5-Dimethylfuran; Benzofuran; Dibenzofuran
Structure
Point group	C2v
	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

Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans.

Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature. It is soluble in common organic solvents, including alcohol, ether, and acetone, and is slightly soluble in water. Its odor is "strong, ethereal; chloroform-like". It is toxic and may be carcinogenic in humans. Furan is used as a starting point for other speciality chemicals.