摘要 |
<p>In the production of anthraquinone wherein naphthalene is oxidized to form naphthoquinone and phthalic anhydride, the naphthoquinone is reacted with butadiene to form tetrahydroanthraquinone, and the tetrahydroanthraquinone is reacted with oxygen to form anthraquinone, the improvement which comprises effecting the reaction of naphthoquinone with butadiene at an elevated temperature in the presence of naphthalene to produce a reaction mixture comprising naphthalene, tetrahydroanthraquinone and phthalic anhydride, separating the naphthalene from said reaction mixture, reacting the remaining mixture comprising tetrahydroanthraquinone and phthalic anhydride at an elevated temperature with molecular oxygen, and removing phthalic anhydride from the oxidation reaction mixture comprising anthraquinone and phthalic anhydride. Because the solvents in the several steps are naphthalene and phthalic anhydride and these are part of the system anyhow, obviously there is no contamination with extraneous materials. The equipment is simple and inexpensive and produces the desired material in high yield and purity.</p> |