CAS number 75-28-5

Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with the molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colourless, odourless gas. It is the simplest alkane with a tertiary carbon atom. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.