Systematic work on the relative reactivities of naphthalene compounds has received little attention in the past. The neglect has arisen out of the importance of a wide variety of naphthalene compounds to industry, so that work has been directed mainly to methods of preparation. Of fundamental importance is the relative reactivities of the 1- and 2- positions in naphthalene to electrophilic and nucleophilic attacking reagents. With two partial exceptions, sulphonation and Friedal-Crafts reactions, reactions involving attack by electrophilic reagent take place in the 1- position (C1). With sulphonation and Friedal-Crafts reactions, temperature and solvent conditions are governing factors upon which the orientation during substitution depends. Unfortunately, evidence regarding the reactivities of C1 and C2 with nucleophilic attacking reagents is neither extensive nor clear-cut.