Butyraldehyde[1]
Names Preferred IUPAC name Other names Identifiers ChEBI ChEMBL ChemSpider ECHA InfoCard 100.004.225 EC Number KEGG RTECS number UNII UN number 1129 Properties 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) 7.6 g/100 mL (20 °C) Solubility Miscible with organic solvents log P 0.88 −46.08·10−6 cm3/mol 1.3766 Viscosity 0.45 cP (20 °C) 2.72 D Thermochemistry[2] 163.7 J·mol−1·K−1 (liquid) 103.4 J·mol−1·K−1 (gas) 246.6 J·mol−1·K−1 (liquid) 343.7 J·mol−1·K−1 (gas) −239.2 kJ·mol−1 (liquid) −204.8 kJ·mol−1 (gas) 2470.34 kJ·mol−1 Hazards GHS labelling: [3] Danger H225, H319[3] P210, P280, P302+P352, P304+P340, P305+P351+P338[3] NFPA 704 (fire diamond) Flash point −7 °C (19 °F; 266 K) 230 °C (446 °F; 503 K) Explosive limits 1.9-12.5% Lethal dose or concentration (LD, LC): 2490 mg/kg (rat, oral) Safety data sheet (SDS) Sigma-Aldrich Related compounds PropionaldehydePentanal Butan-1-olButyric acid, isobutyraldehyde
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 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]
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]
- International Chemical Safety Card 0403