摘要 |
<p>PURPOSE:To efficiently and inexpensively obtain the objective compound in producing the title compound from (monoethyl)naphthalene through ethylation process and liquid-phase oxidation process, by separating an intermediate by pressurizing and crystallizing method and circulating the residue through the ethylation process. CONSTITUTION:In producing 2,6-diethylnaphthalenedicarboxylic acid useful as a polymer material, a dye intermediate, etc., by reacting naphthalene and/or monoethylnaphthalene with one or more ethylating agents selected from ethylene, ethanol and ethyl halide in the presence of an acid catalyst and separating 2,6-diethylnaphthalene (intermediate) from the reaction product and oxidizing in a liquid phase, the intermediate is separated from the ethylated reaction products by a separation method including pressurizing and crystallizing method and the residual reaction product is at least partially circulated through the ethylating process to give the objective compound more efficiently and inexpen sively than a conventional procedure.</p> |