9.10- Dihydrophenanthrene

1 Central Research Department, Monsanto Chemical Company, Dayton 7, Ohio. 

Purification of phenanthrene. 1. By azeotropic distillation.2 A mixture of 300 g. of commercial phenanthrene (Note 1), 90 g. of maleic anhydride, and 600 ml. of xylene, contained in a 2-1. round-bottomed flask, is heated under reflux for 20 hours (Note 2). The initially yellow solution rapidly turns to a dark brown on heating. This solution is cooled to room temperature and filtered by suction to remove any insoluble adduct. The filtrate is then extracted with two 100-ml. portions of dilute sodium hydroxide, and the basic extracts are discarded. The organic phase is next washed with water and saturated sodium chloride solution, and finally is filtered through a layer of anhydrous magnesium sulfate. The excess xylene is removed by distillation, first at atmospheric pressure then the final portions are removed at reduced pressure. The residue, while still hot, is poured into a large mortar and, after solidification, is powdered to a convenient size. The yield of crude phenanthrene is 230-240 g. 

Catalytic reduction. A hydrogenation bomb of approximately 300 ml. total capacity is charged with 29.5 g. (0.17 mole) 

Technical grade phenanthrene (80-90%) is satisfactory for this preparation. 

An electric heating mantle is convenient for this operation. 

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Under different conditions [PdfOAcj2, K2CO3, flu4NBr, NMP], the 1 3 coupling product 86 with 4-aryl-9,10-dihydrophenanthrene units was obtained. The product 86 was transformed into a variety of polycyclic aromatic compounds such as 87 and 88[83], The polycyclic heteroarene-annulated cyclopen-tadicnc 90 is prepared by the coupling of 3-iodopyridine and dicyclopentadiene (89), followed by retro-Diels Alder reaction on thermolysis[84]. 

However, this oxidation to carbonyl failed with the complexes of tetralin, o-chlorotoluene, 9,10-dihydrophenanthrene, and acenaphthalene [109]. The aniline complex can be oxidized to the nitrobenzene complex using H202 in CF3C02H [86] Eq. (38). This reaction parallels the analogous oxidation of aminocobaltici-nium [86, 111],... 

The rates of chlorination of bridged biphenyls have also been measured and show the effect of coplanarity on reactivity. Second-order rate coefficients (104A 2) at 25 °C were fluorene (1,700), 9,10-dihydrophenanthrene (170), 1,2 3,4-di-benzocyclohepta-1,3-diene (9.70), 5-methyl-l,2 3,4-dibenzocyclohepta-l,3-diene... 

Rycroft et al. (1999) identihed the major components of plants from six locations in western Scotland and four from the Azores using nuclear magnetic resonance (NMR) fingerprinting and GC-MS. The terpene P-phellandrene [129], which may be responsible for the aroma of material crushed in the held, was detected in all specimens. The major components, which appear in Fig. 5.6, were shown to be methyl eveminate [444], the four methyl orcellinate derivatives [445 8], the two 9,10-dihydrophenanthrene derivatives [449] and [450], the newly described phthalide killamiensolide [451], and the bibenzyl [453]. Methyl eveminate was the major compound in all 10 specimens other compounds were more varied in their occurrence. Killamiensolide was not isolated as such but was detected when extracts were acetylated yielding, among other compounds, [452]. The presence of the bibenzyl compound [453] in more than trace amounts in P. killarniensis raises the possibility that it represents contamination from P. spinulosa with which it was growing at the one site. 

Recent work identifying Plagiochila retrorsa Gottsche from collections made in the Azores and Madeira establishes a significant range extension for a taxon, known under several other names, which occurs in the southern Appalachian Mountains and in Costa Rica. Rycroft et al. (2001) described morphological and phytochemical characteristics of representative specimens of this liverwort. Phytochemically, P. retrorsa belongs to the 9,10-dihydrophenanthrene chemotype species (major stmctural type is that of compounds 449 and 450). 

The reactions of tetrafluorobenzyne with 9,10-dihydrophenanthrene and phenanthrene yield the expected adducts formed by cyclo-addition at the 1,4-positions 90). The reaction of tetrafluorobenzyne with 1,6-methanocyclodecapentaene (52) was carried out in order to study the mass spectral and thermal fragmentation of (53) 90>. In the event benzocyclopropene and 1,2,3,4-tetrafluoronaphthalene (54) were formed. 

A small amount of 9,10-dihydrophenanthrene is observed (signal at 29.0 ppm) presumably as a result of rapid... 

Synthese von 2,4-Dimethoxy-6-hydroxy-9,10-dihydrophenanthren, by E. Hardegger, N. Rigassi, J. Seres, C. Egli, P. Muller, and K. O. Fitzi (29. Mitteilung, Welkstoffe und Antibiotika), Helv. Chim. Acta, 46 (1963) 2543-2551. 

ET-induced cycloadditions of polycyclic olefins and cycloreversions of cyclobutane species have been studied by ESR spectroscopy [266]. Upon chemical and electrochemical reduction, 2,2 -distyrylbiphenyl rearranges by intramolecular coupling into a bis-benzylic dihydrophenanthrene dianion (Scheme 1), which can be either protonated to a 9,10 -dibenzyl-9,10-dihydrophenanthrene or oxidatively coupled to a cyclobutane species. It is interesting to note that the intramolecular bond... 

Bezalel et al. (1996) reported that the white rot fungus Pleurotus ostreatus, grown in basidiomycetes rich medium, metabolized 94% of the phenanthrene added. Approximately 52% was converted to /rans-9,10-dihydroxy-9,10-dihydrophenanthrene (28%), 2,2 -diphenic acid (17%), and unidentified metabolites (17%). In addition, 3% was mineralized to carlaon dioxide. Sack et al. (1997) reported that phenanthrene was degraded by an Aspergillus niger sixain isolated from a mineral oil-contaminated soil in La Plata, Argentina. The major metabolite was identified via GC/MS as 1-methoxyphenanthrene. Two minor metabolites identified were 1- and 2-phenanthrol. 

When phenanthrene (0.65 mg/L) in hydrogen-saturated deionized water was exposed to a slurry of palladium catalyst (1%) at room temperature for approximately 2 h, 1,2,3,4,5,6,7,8-octahydro-phenanthrene and l,2,3,4,4a,9,10,10a-octahydrophenanthrene formed as products via the intermediates 1,2,3,4-tetrahydrophenanthrene and 9,10-dihydrophenanthrene, respectively (Schiith and Reinhard, 1997). 

Uses Explosives dyestuffs biochemical research synthesis of drugs preparation of 9,10-phen-anthrenequinone, 9,10-dihydrophenanthrene, 9-bromophenanthrene, 9,10-dibromo-9,10-dihydro-phenanthrene, and many other organic compounds. 

The lower yields of pyridine-solubles obtained with tetralin compared to 9,10-dihydrophenanthrene (Table ni) and even to naphthalene and pyrene for the THF-extracted coal (Table m. Figures 1 and 2) again are probably attributable to tetralin being largely vaporised at liquefaction temperatures. 

Figure 3. Conversion of THF-extracted Linby coal with 9,10-dihydrophenanthrene at 400 " C to THF-solubles % Normal extraction After presoak at 250 " C for 1 hour.

Chemical test using sulphur as an hydrogen acceptor Sulphur will readily accept donatable hydrogen to produce H2S whose partial pressure will be proportional to the concentration of H-donors. This reaction provides a simple method for monitoring H-donors contents and initial experiments showed that only small amounts of sulphur and the hydrogen donor compound were needed for the reaction. The method was calibrated using 0.5 g of sulphur with various amounts of 9,10 dihydrophenanthrene (H2) which were reacted at 275 C in a 10 cm3 microautoclave. Plots of pressure vs. time (Figure 3) indicates that an equilibrium pressure was reached in 30 mins or less. 

Liquefaction reactivity experiments were conducted in a 20 cm- tubing bomb reactor attached to an agitator and immersed in a fluidized sandbath. Table II lists reaction conditions used in these runs. A non-hydrogen donor vehicle (1-methylnaphthalene, 1-MN) and a hydrogen donor vehicle (9,10-dihydrophenanthrene, DHP) were used as solvents (2/1 solvent/coal wt. ratio). Coal conversion was monitored using THF extraction data corrected for the intrinsic THF solubility of untreated and treated coals. 

Benzoyl cyanide azine (5%) 9,10-dicyano-9,10-dihydrophenanthrene (8%) 9,10-dicyanophenan-threne (11%) and an unidentified product (6%). 

The partially hydrogenated ring of dihydtocorannulene constitutes a 1,3-cyclo-hexadiene ring, a system that has been well-studied with respect to its geometry and the conformational preferences of substituents. However, the curvature of the corannulene surface introduces an additional stereochemical factor that makes the conformational analysis especially interesting. 1,3-Cyclohexadiene (23) and 9,10-dihydrophenanthrene (24) serve as models they are structurally similar systems, and their stereochemistry and conformational preferences are well documented in the literature. In both cases, the reduced ring adopts a nonplanar, semi-chair conformation of symmetry. 

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