Butanes

Butanes

Butanes, C₄H₁₀. Both n- and isobutene occur in natural gas and petroleum gas, and they may be separated by fractional distillation under pressure. The butanes are used as a liquid fuel and for the preparation of various compounds.

n-Butane, b.p., -0.5^oC, may be prepared by the Wurtz reaction :

2CH₃CH₂I + 2Na  →  CH₃CH₂CH₂CH₃ +2NaI

Isobutane, b.p., -10.2^oC, may be prepared by treating t-butyl iodide with a zinc-copper couple in ethanol :

(CH₃)₃CO   ^{e; H+}   (CH₃)₃CH + HI