Butyraldehyde, also known as butanal, is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula CH₃(CH₂)₂CHO. This compound is the

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

derivative of

butane Butane () is an alkane with the formula C4H10. Butane exists as two isomers, ''n''-butane with connectivity and iso-butane with the formula . Both isomers are highly flammable, colorless, easily liquefied gases that quickly vaporize at ro ...

. It is a colorless flammable

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

with an unpleasant smell. It is miscible with most organic solvents.

Production

Butyraldehyde is produced almost exclusively by the

hydroformylation In organic chemistry, hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes () from alkenes (). This chemical reaction entails the net addition of a formyl group () and a hydrogen ...

propylene Propylene, also known as propene, is an unsaturated organic compound with the chemical formula . It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like o ...

: : CH₃CH=CH₂ + H₂ + CO → CH₃CH₂CH₂CHO Traditionally, hydroformylation was catalyzed by cobalt carbonyl but

rhodium Rhodium is a chemical element; it has symbol Rh and atomic number 45. It is a very rare, silvery-white, hard, corrosion-resistant transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isot ...

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 In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At ...

of ''n''-butanol. At one time, it was produced industrially by the catalytic

hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated ...

of crotonaldehyde, which is derived from

acetaldehyde Acetaldehyde (IUPAC systematic name ethanal) is an organic compound, organic chemical compound with the chemical formula, formula , sometimes abbreviated as . It is a colorless liquid or gas, boiling near room temperature. It is one of the most ...

Reactions and uses

Butyraldehyde undergoes reactions typical of alkyl

s, and these define many of the uses of this compound. Important reactions include

to the alcohol,

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

to the acid, and base-catalyzed condensation. In the presence of a base, two equivalents of butyraldehyde undergoe

aldol condensation An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration t ...

to give 2-ethylhexenal. This unsaturated aldehyde is then partially

hydrogenated Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organi ...

to form 2-ethylhexanal, a precursor to

plasticizer A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizer ...

s such as

bis(2-ethylhexyl) phthalate Bis(2-ethylhexyl) phthalate, di-2-ethylhexyl phthalate, diethylhexyl phthalate, diisooctyl phthalate, DEHP; incorrectly — dioctyl phthalate, DIOP) is an organic compound with the formula C6H4(CO2C8H17)2. DEHP is the most common member of the cl ...

. Butyraldehyde is a component in the two-step synthesis of

trimethylolpropane 300 C--> Trimethylolpropane (TMP) is the organic compound with the formula CH3CH2C(CH2OH)3. This colourless to white solid with a faint odor is a triol. Containing three hydroxy functional groups, TMP is a widely used building block in the polymer ...

, which is used for the production of alkyd resins.

References

External links

* {{Authority control Flavors Alkanals Foul-smelling chemicals