Title: Furfural
CAS Registry Number: 98-01-1
CAS Name: 2-Furancarboxaldehyde
Additional Names: 2-furaldehyde; pyromucic aldehyde; artificial oil of ants; "furfurol"
Molecular Formula: C5H4O2
Molecular Weight: 96.08
Percent Composition: C 62.50%, H 4.20%, O 33.30%
Literature References: Occurs in some essential oils. Prepd industrially from pentosans which are contained in cereal straws and brans. Laboratory prepn from corncobs: R. Adams, V. Voorhees, Org. Synth. coll. vol. I, 280 (2nd ed., 1941). May also be prepd from pyridine. Toxicity study: P. M. Jenner et al., Food Cosmet. Toxicol. 2, 327 (1964).
Properties: Colorless oily liq. Peculiar odor, somewhat resembling the odor of benzaldehyde. Turns yellow to brown on exposure to air and light and resinifies (the polymerization is greatly accelerated by hot alkali). d425 1.1563. bp760 161.8°; bp100 103°; bp20 67.8°; bp1.0 18.5° mp -36.5°. Volatile in steam. nD20 1.5261. Absorption spectrum: Purvis, J. Chem. Soc. 97, 1655 (1910). Sol in 11 parts water; very sol in alcohol, ether. Flash pt, closed cup, 140°F (60°C); open cup, 155°F (68°C). Lower explosive limit: 2.1% by vol in air. Autoignition temp 797°F (392°C). Keep in airtight container and protect from light. LD50 orally in rats: 127 mg/kg (Jenner).
Melting point: mp -36.5°
Boiling point: bp760 161.8°; bp100 103°; bp20 67.8°; bp1.0 18.5°
Flash point: Flash pt, closed cup, 140°F (60°C); open cup, 155°F (68°C)
Index of refraction: nD20 1.5261
Density: d425 1.1563
Toxicity data: LD50 orally in rats: 127 mg/kg (Jenner)
CAUTION: Potential symptoms of overexposure are irritation of eyes, skin and upper respiratory system; headache; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 150.
Use: In the manufacture of furfural-phenol plastics such as Durite; in solvent refining of petroleum oils; in the prepn of pyromucic acid. As a solvent for nitrated cotton, cellulose acetate, and gums; in the manuf of varnishes; for accelerating vulcanization; as insecticide, fungicide, germicide; as reagent in analytical chemistry. In the synthesis of furan derivatives.
Furfuryl Alcohol Furfurylmethylamphetamine Furonazide Furoyl Chloride Furtrethonium

Furfural structure.png Furfural-3D-vdW.png
CAS number 98-01-1 YesY
PubChem 7362
ChemSpider 13863629 YesY
KEGG C14279 YesY
Jmol-3D images Image 1
Molecular formula C5H4O2
Molar mass 96.08 g mol−1
Appearance Colorless oil
Odor Almond-like[1]
Density 1.16 g/mL (20 °C)[2]
Melting point −37 °C; −35 °F; 236 K ([2])
Boiling point 162 °C; 324 °F; 435 K ([2])
Solubility in water 83 g/L[2]
Flash point 62 °C; 144 °F; 335 K
LD50 300–500 mg/kg (oral, mice)[3]
Related compounds
Related furan-2-carbaldehydes Hydroxymethylfurfural


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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Furfural is an organic compound derived from a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. The name furfural comes from the Latin word furfur, meaning bran, referring to its usual source.

Furfural is a heterocyclic aldehyde, with the ring structure shown at right. Its chemical formula is OC4H3CHO. It is a colorless oily liquid with the odor of almonds, but upon exposure to air samples quickly become yellow.

It is one of the components found in vanilla.