Isobutanol is an alkyl alcohol that is propan-1-ol substituted by a methyl group at position 2.it is clear colorless liquid with a sweet odor. Isobutyl alcohol,is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as i-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters.