The invention relates to a preparation method of 7-methoxynaphthalene
acetonitrile. The preparation method comprises the following steps: reacting 7-methoxy-1-
tetralone with
copper bromide under the action of a catalyst to generate 7-methoxy-2-bromo-1,2,3,4-
tetralone; reacting 7-methoxy-2-bromo-1,2,3,4-
tetralone under the
catalysis of a
heteropoly acid to obtain 7-methoxy-1,4-dihydronaphthalone; and directly condensing 7-methoxy-1,4-dihydronaphthalone with
cyanoacetic acid in the presence of
benzylamine and
heptanoic acid to obtain 7-methoxynaphthalene
acetonitrile. The preparation method of the catalyst comprises the following steps: mixing carrier particles and a
metal salt solution, adjusting the pH to alkaline, washing,
drying, immersing in a
sulfuric acid solution, filtering, and then
roasting to obtain the catalyst. The carrier particles are aluminum
oxide or
silicon dioxide, and the
metal salt solution is a
salt solution of Zr, Ti or Sn. The method reduces the difficulty of purification, improves the yield and purity, and reduces the cost.