Normal Butanol

N-Butanol is used as an ingredient in perfumes and as a solvent for the extraction of essential oils. n-Butanol is also used as an extractant in the manufacture of antibiotics, hormones, and vitamins; a solvent for paints, coatings, natural resins, gums, synthetic resins, dyes, alkaloids, and camphor.Butanol is primarily used as a solvent, as an intermediate in chemical synthesis, and as a fuel. It is sometimes also called biobutanol when produced biologically.

Butanol (also called butyl alcohol (or in Greek)) is a four-carbon alcohol with a formula of C4H9OH, which occurs in five isomeric structures, from a straight-chain primary alcohol to a branched-chain tertiary alcohol;[1] all are a butyl or isobutyl group linked to a hydroxyl group (sometimes represented as BuOH, n-BuOH, and i-BuOH). These are n-butanol, 2 stereoisomers of 2-butanol, tert-butanol, and isobutanol. Butanol is primarily used as a solvent, as an intermediate in chemical synthesis, and as a fuel. It is sometimes also called biobutanol when produced biologically.

Contents

• Isomers
• Toxicity

Isomers

• The unmodified term butanol usually refers to the straight chain isomer with the alcohol functional group at the terminal carbon, which is also known as n-butanol or 1-butanol. The straight chain isomer with the alcohol at an internal carbon is sec-butanol or 2-butanol. The branched isomer with the alcohol at a terminal carbon is isobutanol or 2-methyl-1-propanol, and the branched isomer with the alcohol at the internal carbon is tert-butanol or 2-methyl-2-propanol.
• The butanol isomers have different melting and boiling points. n-butanol and isobutanol have limited solubility, sec-butanol has substantially greater solubility, while tert-butanol is fully miscible with water above tert-butanol's melting point. The hydroxyl group makes the molecule polar, promoting solubility in water, while the longer hydrocarbon chain mitigates the polarity and reduces solubility. The shorter chain molecules of methanol, ethanol, propanol, and tert-butanol are fully miscible with water, while n-butanol is only moderately soluble because of the diminishing polarity in the longer hydrocarbon group.

Toxicity
Like many alcohols, butanol is considered toxic. It has shown low order of toxicity in single dose experiments to laboratory animals.[2][3] and is considered safe enough for use in cosmetics. Brief, repeated overexposure with the skin can result in depression of the central nervous system, as with other short-chain alcohols. Exposure may also cause severe eye irritation and moderate skin irritation. The main dangers are from prolonged exposure to fumes. In extreme