Title: Butyraldehyde
CAS Registry Number: 123-72-8
CAS Name: Butanal
Molecular Formula: C4H8O
Molecular Weight: 72.11
Percent Composition: C 66.62%, H 11.18%, O 22.19%
Line Formula: CH3CH2CH2CHO
Literature References: Prepn from butyryl chloride: Brown, Tsukamoto, J. Am. Chem. Soc. 83, 2016 (1961); by reduction of corresponding nitrile: Gaiffe, Pallaud, Compt. Rend. 254, 496 (1962); by alkali aluminum hydride reduction of methyl butyrate: Zakharkin et al., Tetrahedron Lett. 1963, 208; by oxidation of butanol: Harrison, Proc. Chem. Soc. London 1964, 110. Usually manuf by catalytic dehydrogenation of butanol, catalytic hydrogenation of crotonaldehyde, or by the oxo process from propene, e.g., see: Dunbar, Arnold, J. Org. Chem. 10, 501 (1945); Horn, Ind. Eng. Chem. 51, 655 (1959); W. L. Faith et al., Industrial Chemicals (John Wiley, New York, 3rd ed., 1965) pp 183, 304-305. Toxicity study: Smyth et al., Arch. Ind. Hyg. Occup. Med. 4, 119 (1951). Review: P. D. Sherman in Kirk-Othmer Encyclopedia of Chemical Technology vol. 4 (Wiley-Interscience, New York, 3rd ed., 1978) pp 376-386.
Properties: Flammable liquid. bp 74.8°. mp -99°. Closed-cup flash pt -6.67°C (20°F). d420 0.8016. nD20 1.379. Soly in water at 25°, 7.1 (wt-%): Smith, Bonner, Ind. Eng. Chem. 43, 1169 (1951). Miscible with ethanol, ether, ethyl acetate, acetone, toluene, many other organic solvents and oils. Single-dose LD50 orally in rats: 5.89 g/kg (Smyth).
Melting point: mp -99°
Boiling point: bp 74.8°
Flash point: flash pt -6.67°C (20°F)
Index of refraction: nD20 1.379
Density: d420 0.8016
Toxicity data: Single-dose LD50 orally in rats: 5.89 g/kg (Smyth)
CAUTION: May act as irritant, narcotic.
Use: Chiefly in the manuf of rubber accelerators, synthetic resins, solvents, plasticizers.
Butyric Acid Butyric Anhydride Butyroin Butyrolactone Butyronitrile

Skeletal structure
Flat structure
Ball-and-stick model
CAS number 123-72-8 YesY
PubChem 261
ChemSpider 256 YesY
UNII H21352682A YesY
KEGG C01412 YesY
ChEBI CHEBI:15743 YesY
Jmol-3D images Image 1
Molecular formula C4H8O
Molar mass 72.11 g/mol
Appearance colorless liquid
Odor pungent, aldehyde odor
Density 0.8016 g/mL
Melting point −96.86 °C; −142.35 °F; 176.29 K
Boiling point 74.8 °C; 166.6 °F; 347.9 K
Solubility in water 7.6 g/100 mL (20 °C)
Solubility miscible with ethanol, ether, toluene
very soluble in acetone, benzene
slightly soluble in chloroform
log P 0.88
Refractive index (nD) 1.3766
Viscosity 0.45 cP (20 °C)
Dipole moment 2.72 D
Std enthalpy of
combustion ΔcHo298
2470.34 kJ/mol
MSDS Sigma-Aldrich
EU Index 605-006-00-2
EU classification Flammable (F)
R-phrases R11
S-phrases (S2), S9, S29, S33
NFPA 704
NFPA 704.svg
Flash point −7 °C; 19 °F; 266 K
Autoignition temperature 230 °C; 446 °F; 503 K
Explosive limits 1.9–12.5%
LD50 2490 mg/kg (rat, oral)
Related compounds
Related aldehyde Propionaldehyde
Related compounds Butan-1-ol
Butyric acid, isobutyraldehyde
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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

Butyraldehyde, also known as butanal, is an organic compound with the formula CH3(CH2)2CHO. This compound is the aldehyde derivative of butane. It is a colourless flammable liquid with an acrid smell. It is miscible with most organic solvents.