摘要 |
<p>There is disclosed a mass production process of 1,4,5,8-naphthalene tetracarboxylic acid with high collection efficiency. In the presence of an alkaline metallic catalyst, 1,3-butadiene was added to the ethyl radicals of ethyl-p-xylene, and cyclized to 1,4,5,8-tetramethyl-1,2,3,4-tetrahydronaphthalene which was further dehydrogenated and oxidized to obtain 1,4,5,8-naphthalene tetracarboxylic acid, so that a constant supply of inexpensive 1,4,5,8-naphthalene tetracarboxylic acid can be achieved as an intermediate raw material for dye, pigment, resins, or the like.</p> |