Phthalic anhydride from phenanthrene

When mixtures of anthracene and phenanthrene, such as are obtained by removing carbazole from anthracene press cake by caustic fusion, arc oxidized, mixtures of phthalic anhydride and anthraquinone result. A separation of these valuable products is effected by washing out the acids with an alkali solution and recovering as sodium salts or as acids by addification subsequent to removal of anthraquinone by filtration. The products may be distilled or sublimed to separate from any unoxidized material that may be present. Maleic acid may also be present in the products to a small extent and is recovered with the phthalic anhydride from which it must be removed as an impurity.88... 

The direct synthesis of anthraquinone from phthalic anhydride and benzene has been reported to proceed over zeolite Beta [50] in a shape selective manner. In a conventional anthraquinone synthesis, anthracene is used as a feedstock for oxidation. Once there is a shortage of it in the market, additional anthracene could be produced by isomerization of its isomer, viz. phenanthrene. This, however, is not possible by direct isomerization of the trinuclear aromatic system but involves the partially (symmetrically) hydrogenated species. Consequently, isomerization of symmetrical octahydrophenanthrene to symmetrical octahydro-anthracene was studied by Song and Moffatt [51]. As sketched in Figure 3, a high yield of symmetrical octahydroanthracene can be obtained over zeolite H-mordenite (ngj/nyy = 8) at 250 °C (liquid phase, decalin as solvent). These examples show that (shape selective) catalysis on zeolites is more and more expanding into the conversion of polycyclic aromatics, and we foresee continued interest and success in this field of zeolite catalysis. 

Phenanthrene. Phenanthrene is isomeric with anthracene and is obtained from anthracene press cake by use of selective solvents after carbazole removal by caustic fusion and distillation. It may be oxidized to plienanthraquinone, which is used in the preparation of dye stuffs, and phthalic anhydride in the same processes used for the other aromatic hydrocarbons.41 Phthalic anhydride is the main product and unless conditions are very carefully controlled plienanthraquinone forms in only small amounts.48... 

Benzanthracene, Benzlajanthracene 2,3-benzphenanthrene tetraphene benzanthrene naphthanthra-cene. C,HI2 mol wt 228.28. C 94.70%, H 5.30%. Occurs in coal tan Cook el at. J. Chcm. Soc. 1933, 395. Synthesis from naphthalene and phthalic anhydride Elbs, Her. 19, 2209 (1886). From o-to uy] naphthalene Fieser, Dietz, Ber. 62, 1827 (1929). From phenanthrene and succinic anhydride Haworth, Mavin, J. Chcm. Soc. 1933, 1012. Absorption spectrum Capper, Marsh, J. Chem. Soc. 1926, 726 Clar. Ber. 65, 507 (1932) Mayneord, Roe, Proc. Roy. Soc. London A152, 299 (1935). Review E. Clar. Polycyclic Hydrocarbons (Academic Press, New York, 1964) 2 vols. 

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