1,8-Naphthalene di:carboxylic acid(s) and anhydride(s) prepn. - by oxidn. of acenaphthene using promoted heavy metal cpd. catalyst and aliphatic acid anhydride accelerator

摘要

Prepn. of 1,8-naphthalene dicarboxylic acids or their acid anhydrides comprises oxidising acenaphthene or an acenaphthene having a substit. other than OH or NH2 with mol. oxygen in an organic solvent in the presence of (a) a heavy metallic cpd. and opt. an (in)organic bromine cpd. as catalyst(s); (b) lower aliphatic acid anhydride as accelerator; and opt. (c) a promotor consisting of aliphatic tert. amine, aromatic tert. amine, N,N-dialkyl-substd. amide, heterocyclic nitrogen or a base. The yield of the end-product is increased. Suitably the heavy metallic cpds. are salts, oxides or hydroxides of Co, Mn, Cr, Ce, Fe, Ni, Cu, Ru, Pd, Pt or Ir, e.g. cobalt acetate or maganese acetate. It is pref. used in an amt. of 0.01-0.2 mol. relative to the cpd. to be oxidised. The reaction temp. is pref. =30 degrees C. Specifically the initial stage of the reaction is 30-90 degrees C and as the reaction proceeds, the temp. is raised to 90-140 degrees C.