text: Sulfonation to give the 1- and 2-sulfonic acid occurs readily:
  Further sulfonation give di-, tri-, and tetrasulfonic acids.
  Lithiation
  Analogous to the synthesis of phenyllithium is the conversion of 1-bromonaphthalene to 1-lithionaphthalene, by lithium–halogen exchange:
  C10H7Br  +  BuLi   →    C10H7Li  +  BuBr
  The resulting lithionaphthalene undergoes a second lithiation, in contrast to the behavior of phenyllithium. These 1,8-dilithio derivatives are precursors to a host of peri-naphthalene derivatives.
  Reduction and oxidation
  With alkali metals, naphthalene forms the dark blue-green radical anion salts such as sodium naphthalene, Na+C10H. The naphthalene anions are strong reducing agents.
  Naphthalene can be hydrogenated under high pressure in the presence of metal catalysts to give 1,2,3,4-tetrahydronaphthalene(), also known as tetralin. Further hydrogenation yields decahydronaphthalene or decalin ().
  Oxidation with  in the presence of vanadium pentoxide as catalyst gives phthalic anhydride:
  C10H8  +  4.5 O2   →   C6H4(CO)2O  +  2 CO2  +  2 H2O
  This reaction is the basis of the main use of naphthalene. Oxidation can also be effected using conventional stoichiometric chromate or permanganate reagents.
  Production
  Most naphthalene is derived from coal tar. From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during petroleum refining, but present-day production is mainly from coal tar. Approximately 1.3M tons are produced annually.