| IUPAC name
| Preferred IUPAC name
| Other names
|Molar mass||68.075 g/mol|
|Density||0.9731 g/cm3 (20 °C)|
|Melting point||−85.6 °C (−122.1 °F; 187.6 K)|
|Boiling point||31.3 °C (88.3 °F; 304.4 K)|
|1 g/100 ml (25 °C)|
|Solubility||Miscible with glacial acetic acid, acetone, benzene, chloroform, ethanol|
|Vapor pressure||600 mmHg at 25 °C|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
|Flash point||−69 °C (−92 °F; 204 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
| 200-2,000 mg/kg (rat, oral)|
5.2 mg/kg (rat, IP)
7 mg/kg (mouse, IP)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Furan (C4H4O) is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen. Chemical compounds containing such rings are also referred to as furans.
Furan is aromatic because one of the lone pairs of electrons on the oxygen atom is delocalized into the ring, creating a 4n + 2 aromatic system similar to benzene. Because of the aromaticity, the molecule is flat and lacks discrete double bonds. Due to its aromaticity, furan's behavior is quite dissimilar to that of the more typical heterocyclic ethers such as tetrahydrofuran.
Furan is a colorless, flammable, highly volatile liquid with a boiling point slightly above room temperature. It is soluble in common organic solvents, including acetone, diethyl ether, ethanol and toluene, but is only slightly soluble in water. Its odor has been described as "strong, ethereal, chloroform-like".
Furan is sold by chemical suppliers.
Industrially, furan is manufactured by the palladium-catalyzed decarbonylation of furfural, or by the copper-catalyzed oxidation of 1,3-butadiene.
It can also be prepared directly by thermal decomposition of pentose-containing materials, and cellulosic solids, especially pine wood.
- Make THF via hydrogenation of furan
- Make pyrole
Furan is volatile and flammable. It is irritant, toxic and carcinogen. Exposure to furan at doses about 2000 times the projected level of human exposure from foods increases the risk of hepatocellular tumors in rats and mice and bile duct tumors in rats. Furan is therefore listed as a possible human carcinogen.
Furan is found in heat-treated commercial foods and is produced through thermal degradation of natural food constituents. It can be found in roasted coffee, instant coffee, and processed baby foods, though the amount is small.
In closed bottles, in well ventilated, dark fireproof cabinets.
Should be mixed with a more flammable solvent and burned outside or in an incinerator.