Furfural

Furfural

Names
IUPAC name Furan-2-carbaldehyde
Other names Fural, furan-2-carboxaldehyde, furfuraldehyde, 2-furaldehyde, pyromucic aldehyde
Identifiers
Jmol-3D images	Image
SMILES c1cc(oc1)C=O
Properties
Chemical formula	C5H4O2
Molar mass	96.09
Appearance	Colorless oil
Odor	Almond-like
Density	1.16 g/mL (20 °C)
Melting point	−37 °C (−35 °F; 236 K)
Boiling point	162 °C (324 °F; 435 K)
Solubility in water	83 g/L
Vapor pressure	2 mmHg (20°C)
Hazards
Safety data sheet	Sigma-Aldrich
Flash point	62 °C (335 K, 144 °F)
Related compounds
Related compounds	Furan
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Furfural is an organic compound, a heterocyclic aldehyde, with the chemical formula C₅H₄O₂. It is derived from a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust.

Properties

Chemical

Hydrogenating furfural yields tetrahydrofuran and derivatives, such as 2-methyltetrahydrofuran, and furfuryl alcohol.

Palladium-catalyzed decarbonylation of furfural will yield furan.

When heated in the presence of acids, furfural irreversibly solidifies into a hard thermosetting resin.

Physical

Furfural is a colorless oily liquid, with an almond-like smell, which quickly darkens when exposed to air. It is poorly soluble in water and alkanes. Furfural is however soluble in most polar organic solvents.

Availability

Furfural is sold by many chemical suppliers.

Preparation

Furfural can be obtained by heating hemicellulose with dilute sulfuric acid. Through this process, the hemicellulose undergoes hydrolysis to yield these sugars, mainly xylose. Under the same conditions of heat and acid, xylose and other five carbon sugars undergo dehydration, losing three water molecules, resulting furfural:

C₅H₁₀O₅ → C₅H₄O₂ + 3 H₂O

Corn cobs, which are cheaply and readily available, can be used as a source of sugars, offering a good yield. Fresh corn cobs have been found to have a better yield than older ones.

D-Ribose will form furfural on heating with sulfuric acid.

Projects

• Make furfuryl alcohol
• Make 2-methyltetrahydrofuran
• Make tetrahydrofuran
• Make furan

Handling

Safety

Furfural is toxic and should be handled with care. It is a skin irritant and chronic skin exposure can lead to skin allergy as well as an unusual susceptibility to sunburn.

Storage

Furfural should be stored in closed bottles, away from air to prevent it from turning brown.

Disposal

Furfural can be safely burned.

References

Relevant Sciencemadness threads

• furfural