butan2ol

Butan-2-ol, also known as sec-butanol or 2-butanol, is an organic compound with the formula C4H10O. It is a secondary alcohol in which the hydroxyl group is attached to the second carbon of a four-carbon chain. The molecule has a chiral center at the second carbon, so it exists as two enantiomers (R and S); in many practical contexts the racemate is used, though enantiomerically enriched forms can be prepared.

Physically, butan-2-ol is a colorless, flammable liquid with a boiling point around 99.5°C and a density near 0.81 g/mL at 20°C. It is miscible with many organic solvents; its solubility in water is moderate and varies with temperature. The compound is commonly encountered as a solvent and as an intermediate in organic synthesis.

Industrial production of butan-2-ol typically occurs by acid-catalyzed hydration of but-2-ene (cis- or trans-2-butene) to yield 2-butanol, or by the reduction of 2-butanone. It serves as a versatile solvent in coatings, inks, and pharmaceutical or chemical syntheses, and is an intermediate for the manufacture of other chemicals, including 2-butanone (methyl ethyl ketone) and various esters.

Reactivity and transformations include oxidation to 2-butanone, dehydration to produce butenes under acid catalysis, esterification of the alcohol, and various substitutions at the hydroxyl-bearing carbon under appropriate conditions. Safety considerations reflect its flammability and potential for irritation; proper ventilation and standard handling practices are advised to minimize exposure.