When n-Hexane is heated with anhydrous AlCl3 and HCl gas at 573K under a pressure of about 30−35atm it Isomerises to give a branched chain alkanes.
CH3(CH2)4CH3→△HClAnhy.AlCl32−methylpentane(CH3)2CHCH2CH2CH3+3−methylpentane
Major product in the above reaction is 2-methylpentane.