5154. Isobutyraldehyde

Nomenclature

CAS number: 78-84-2
2-Methylpropanal; isobutylaldehyde; isobutyric aldehyde; 2-methylpropionaldehyde; 2-propanecarboxaldehyde.
C4H8O; mol wt 72.11.
C 66.62%, H 11.18%, O 22.19%.

Description and references

Manuf by the oxo process from propylene, carbon monoxide, and hydrogen at 130-160° and 1500-3000 psi in the presence of a cobalt catalyst: Roelen, US 2327066 (1943); also prepared by air oxidation of isobutyl alcohol: Fossek, Monatsh. Chem. 2, 614 (1881); Lipp, Ann. 205, 2 (1880). Toxicity study: Smyth et al., Arch. Ind. Hyg. Occup. Med. 10, 61 (1954). Review: P. D. Sherman in Kirk-Othmer Encyclopedia of Chemical Technology vol. 4 (Wiley-Interscience, New York, 3rd ed., 1978) pp 376-386.

Chemical structure

Properties

Pungent odor. d420 0.7938. mp 65.9°. bp760 64°. nD20 1.3730. Heat of combustion 599.9 kcal. Flash pt (open cup) <20°F. Soly in water at 20°: 11 g/100 ml H2O. Flammable. Miscible with ethanol, ether, carbon disulfide, acetone, benzene, toluene, chloroform. Forms an azeotrope with water contg 94% isobutyraldehyde. The azeotrope bp760 59°. Weight per gallon of isobutyraldehyde: 6.55 lbs. Oxidizes slowly on exposure to air, forming isobutyric acid. LD50 orally in rats: 3.7 g/kg (Smyth).

Use

In the synthesis of pantothenic acid, valine, leucine, cellulose esters, perfumes, flavors, plasticizers, resins, gasoline additives.