Butyraldehyde

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 colorless flammable liquid with an unpleasant smell. It is miscible with most organic solvents.

Butyraldehyde^[1]

Structural formula of butyraldehyde Flat structure
Ball-and-stick model
Names
Preferred IUPAC name Butanal
Other names Butyraldehyde
Identifiers
CAS Number	123-72-8 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:15743 Y
ChEMBL	ChEMBL1478334
ChemSpider	256 Y
ECHA InfoCard	100.004.225
EC Number	204-646-6
KEGG	C01412 Y
PubChem CID	261
RTECS number	ES2275000
UNII	H21352682A Y
UN number	1129
CompTox Dashboard (EPA)	DTXSID8021513
InChI InChI=1S/C4H8O/c1-2-3-4-5/h4H,2-3H2,1H3 Y Key: ZTQSAGDEMFDKMZ-UHFFFAOYSA-N Y InChI=1/C4H8O/c1-2-3-4-5/h4H,2-3H2,1H3 Key: ZTQSAGDEMFDKMZ-UHFFFAOYAZ
SMILES O=CCCC
Properties
Chemical formula	C4H8O
Molar mass	72.107 g·mol−1
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)
Critical point (T, P)	537 K (264 °C), 4.32 MPa (42.6 atm)
Solubility in water	7.6 g/100 mL (20 °C)
Solubility	Miscible with organic solvents
log P	0.88
Magnetic susceptibility (χ)	−46.08·10−6 cm3/mol
Refractive index (nD)	1.3766
Viscosity	0.45 cP (20 °C)
Dipole moment	2.72 D
Thermochemistry[2]
Heat capacity (C)	163.7 J·mol−1·K−1 (liquid) 103.4 J·mol−1·K−1 (gas)
Std molar entropy (S⦵298)	246.6 J·mol−1·K−1 (liquid) 343.7 J·mol−1·K−1 (gas)
Std enthalpy of formation (ΔfH⦵298)	−239.2 kJ·mol−1 (liquid) −204.8 kJ·mol−1 (gas)
Std enthalpy of combustion (ΔcH⦵298)	2470.34 kJ·mol−1
Hazards
GHS labelling:
Pictograms	[3]
Signal word	Danger
Hazard statements	H225, H319[3]
Precautionary statements	P210, P280, P302+P352, P304+P340, P305+P351+P338[3]
NFPA 704 (fire diamond)	3 3 0
Flash point	−7 °C (19 °F; 266 K)
Autoignition temperature	230 °C (446 °F; 503 K)
Explosive limits	1.9–12.5%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2490 mg/kg (rat, oral)
Safety data sheet (SDS)	Sigma-Aldrich
Related compounds
Related aldehyde	Propionaldehyde Pentanal
Related compounds	Butan-1-ol Butyric acid, isobutyraldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Production

Butyraldehyde is produced almost exclusively by the hydroformylation of propylene:

CH₃CH=CH₂ + H₂ + CO → CH₃CH₂CH₂CHO

Traditionally, hydroformylation was catalyzed by cobalt carbonyl but rhodium complexes are more common. The dominant technology involves the use of rhodium catalysts derived from the water-soluble ligand tppts. An aqueous solution of the rhodium catalyst converts the propylene to the aldehyde, which forms a lighter (less dense) immiscible phase. About 6 billion kilograms are produced annually in this manner. Butyraldehyde can be produced by the catalytic dehydrogenation of n-butanol. At one time, it was produced industrially by the catalytic hydrogenation of crotonaldehyde, which is derived from acetaldehyde.^[4]

Reactions and uses

Butyraldehyde undergoes reactions typical of alkyl aldehydes, and these define many of the uses of this compound. Important reactions include hydrogenation to the alcohol, oxidation to the acid, and base-catalyzed condensation. In the presence of a base, two equivalents of butyraldehyde undergoe aldol condensation to give 2-ethylhexenal. This unsaturated aldehyde is then partially hydrogenated to form 2-ethylhexanal, a precursor to plasticizers such as bis(2-ethylhexyl) phthalate.^[4]

Butyraldehyde is a component in the two-step synthesis of trimethylolpropane, which is used for the production of alkyd resins.^[5]

A major use of butyraldehyde is in the production of bis(2-ethylhexyl) phthalate, a major plasticizer.