Acetylene can be cyclised using the intermolecular condensation method. That is, when it is treated at high temperature in red hot iron tube at 873K undergoes cyclic polymerization to give benzene. This can be a convenient way to start from a aliphatic compound to benzene. The reaction is given as:

Benzene when treated with nitrating mixture i.e. conc. HNO₃ and H₂SO₄, undergoes nitration to gives nitrobenzene as the major product.