n-Butanol or n-butyl alcohol or normal butanol is a primary alcohol with a 4-carbon structure and the chemical formula C4H9OH. Its isomersinclude isobutanol, 2-butanol, and tert-butanol. Butanol is one of the group of "fusel alcohols" (from the German for "bad liquor"), which have more than two carbon atoms and have significant solubility in water.
n-Butanol occurs naturally as a minor product of the fermentation of sugars and other carbohydrates, and is present in many foods and beverages. It is also a permitted artificial flavorant in the United States, used in butter, cream, fruit, rum, whiskey, ice cream and ices, candy, baked goods and cordials. It is also used in a wide range of consumer products.
The largest use of n-butanol is as an industrial intermediate, particularly for the manufacture of butyl acetate (itself an artificial flavorant and industrial solvent). It is a petrochemical, manufactured from propylene and usually used close to the point of manufacture.
n-butanol is an intermediate in the production of butyl acrylate, butyl acetate, dibutyl phthalate, dibutyl sebacate, and other butyl esters, butyl ethers such as ethylene glycol monobutyl ether, di- and triethylene glycol monobutyl ether, and the corresponding butyl ether acetates. Other industrial uses include the manufacture of pharmaceuticals, polymers, pyroxylin plastics, herbicide esters, printing (e.g., 2,4-D, 2,4,5-T) and butyl xanthate. It is also used as a diluent/reactant in the manufacture of urea formaldehyde and melamine formaldehyde resins.
Butanol is used as a solvent for a wide variety of chemical and textile processes, in organic synthesis, and as a chemical intermediate. It is also used as a paint thinner and a solvent in other coating applications where a relatively slow evaporating latent solvent is preferable, as with lacquers and ambient-cured enamels. It is also used as a component of hydraulic and brake fluids.
Butanol is used in the synthesis of 2-butoxyethanol. A major application for butanol is as a reactant with acrylic acid to produce butyl acrylate, a primary ingredient of water based acrylic paint.
It is also used as a base for perfumes, but on its own has a highly alcoholic aroma.
Salts of butanol are chemical intermediates; for example, alkali metal salts of tert-butanol are tert-butoxides.