Phenanthrene nitration

Both phenanthrene and anthracene have a tendency to undergo addition reactions under the eonditions involved in eertain eleetrophilic substitutions. For example, in the nitration of anthracene in the presence of hydrochloric acid, an intermediate addition product can be isolated. This is a result of the relatively close balance in resonance stabilization to be regained by elimination (giving an anthracene ring) or addition (resulting in two benzenoid rings). 

As discussed in Section 10.3, the system consisting of a diazonium ion and cuprous ions can be used for hydroxy-de-diazoniation at room temperature in the presence of large concentrations of hydrated cupric ions (Cohen et al., 1977 see Schemes 10-7 to 10-9). With (Z)-stilbene-2-diazonium tetrafluoroborate under these conditions, however, the major product of ring closure of the initially formed radical was phenanthrene (64%). When the cupric nitrate was supplemented by silver nitrate the yield increased to 86% phenanthrene. Apparently, the radical undergoes such rapid ring closure that no electron transfer to the cupric ion takes place. 

Peroxyacyl nitrates, see Acetaldehyde, Butane, 2-Bntanone, 2,3-Dimethylbntane Peroxybenzoic acid, see Toluene Peroxynitric acid, see Formaldehyde Peroxypropionyl nitrate, see 2-Methylpentane, Pentane Phenanthrene, see Anthracene, Bis(2-ethylhexyl) phthalate, Naphthalene Phenanthrene-9,10-dione, see Phenanthrene 9,10-Phenanthrenequinone, see Phenanthrene 4-Phenanthroic acid, see Pyrene... 

Tetramethoxy aristolochic acid (80) was obtained by nitration from the corresponding 3,4,6,7-tetramethoxy-phenanthrene-l-carboxylic acid (81), which was obtained from glaucine (82) via exhaustive Hofmann degradation (twice) followed by oxidation. Catalytic hydrogenation with Pd-C afforded the relevant aristolactam (83) (Scheme 10) (82). 

Nitration of arenes. Reaction of 1-naphthol with CAN in acetic acid results in 2,4- and 4,6-dinitro derivatives. The reaction with CAN absorbed on silica gel results in 2-nitro- and 4-nitro-l-naphthol in 42 and 38% yield, respectively. Polynuclear arenes are not oxidized to quinones by CAN supported on silica but are converted mainly into mononitro derivatives. Thus phenanthrene is converted into 2-nitrophenanthrene (45% yield) and 3-nitrophenanthrene (28% yield).1... 

The reactions of the higher hydrocarbons with electrophilic reagents are more complex than of naphthalene. For example, phenanthrene can be nitrated and sulfonated, and the products are mixtures of 1-, 2-, 3-, 4-, and 9-substituted phenanthrenes ... 

Anthracene is even more reactive than phenanthrene and has a greater tendency to add at the 9,10 positions than to substitute. However, the addition products of nitration and halogenation readily undergo elimination to form the 9-substitution products ... 

Thermochemical data are available (Ref 2) on the heats of combustion and formation for all five isomers, on the heats of nitration from various Dinitrotoluenes for the 23,4-, 2,4,5-, and 2,3,6-isomers, and on the heats of crystn for the 2,3,4- and 2,4,5-isomers. Data are also available (Ref 1) on the shock sensitivities of all of the isomers except 2,3,6-, and on the rates of decompn at 140° of the 23,4-, 2,4,5-, and 23,5-isomers. The detonation pressure and the temp coefficient of decompn between 140 and 180° have been measured for the 2,4,5-isomer 2,3,4- and 2,4,5-TNT form addition compds ( 7r-complexes ) at 1 1 molar ratio with several polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene and anthracene) (Ref 2). 2,4,5-TNT forms complexes with 4-aminozaobenzene, 4-aminoacetophenone, bis (2 hydroxy ethyl) amine, and tris (2-hydroxy-ethyl) amine (Ref 1). The first two have a 1 1 molar ratio, the third 1 2, and the fourth 2 1. Upon heating, the two 4-amino compds react with replacement of the 5-nitro group, as discussed below... 

Many polycyclic aromatic amines and aldehydes are commercially available, but their supply is very limited. Preparation of these starting materials is necessary for studying the (3-lactam formation reaction [93]. Nitro compounds are the precursors for the amines. An important task was to prepare polycyclic aromatic nitro compounds, particularly those of chrysene, phenanthrene, pyrene, and dibenzofluorene in good yield. Nitration of these hydrocarbons with concentrated nitric acid in sulfuric acid is a widely used reaction for this purpose. Our research culminated in facile synthesis of polyaromatic nitro derivative 9 starting from polyaromatic hydrocarbons (PAHs) 8 through the use of bismuth nitrate impregnated with clay (Scheme 1) ([94, 95] for some examples of bismuth nitrate-catalyzed reactions... 

A nice example is provided by 10,9-borazarophenanthrene (V). The reactivity numbers for the isoconjugate AH, phenanthrene, are shown in (VI). The lowest numbers are in the 9,1- and 4-positions but the 4-position is sterically hindered. Experiment22 showed that the order of reactivity (nitration in acetic anhydride) for the various positions in phenanthrene was 9 > 1 > 3 4, 2. 

The direct oxidation of arenes to quinones is a reaction with a limited scope [41], Only substrates that form stable quinones give good yields. For example, oxidation of anthracene to stable 9,10-anthraquinone with chromic acid is practiced on industrial scale. Such oxidations are believed to proceed through a series of one-electron oxidation/solvolysis steps. Yields and selectivity may be improved by using a strong one-electron oxidant such as cerium ammonium nitrate (CAN), as in the oxidation of phenanthrene to phenanthrenequinones (Eq. 9) [42]. 

McKie [142] found the yield of the nitration product to be higher when mercuric nitrate was present in nitric acid. Thus for example, phenanthrene, when nitrated with anhydrous nitric acid in the presence of Hg(N03)2, gave nitrophenan-threne in a yield higher by 13% than when nitric acid alone had been used. Likewise the yields of nitro derivatives of phenol and a- naphthol could be increased by addition of mercuric nitrate to dilute nitric acid. 

Nitration of 2,4-dimethylbenzo[/i]quinoline gives the yields at the 7-and 9-positions shown in 11.79 (77MI1), neither position being conjugated with nitrogen. The reason for the higher yield of the 9-isomer is not obvious, especially since in phenanthrene the positional order in nitration (9 > 1 > 3 > 2 > 4) predicts the 7-position of 11.79 to be most reactive. 

Treatment of 2,9-dibromophenanthrene with Pt (Et3P)4 followed by bromine-nitrate exchange gave the desired 60° tecton, 2,9-6/i [/ra 5 -Pt(PEt3)2(N03)]phenanthrene, which with different linear connectors afforded a series of self-assembled supramolecular triangles <03JA5193>. A series of related binuclear metallomacrocycles [Cd(N03)2L]2, where L is an angular exo-bidentate, such as 4-(4 -pyridinyl)(2-pyridinylethynyl) benzene, have been reported... 

Trimethyl phosphate containing phosphorus pentoxide is a useful medium for the halogenation of aromatic substances which are sensitive to hydrogen halides, and also for the nitration of phenanthrene. ... 

Effects of beta-naphtoflavone pretreatment on hepatotoxicity of compounds produced in the ozonation or NO2-nitration of phenanthrene and pyrene in rats. Vet Hum Toxicol 29 113-117. 

A set of fluorophores derived from naphthalene, phenanthrene, pyrene, phenazine and fluorene have been conjugated to the 5 -ends of DNA and RNA to compare their physico-chemical properties. Decreasing the Ji-electron density led to an enhancement in thermal stability, attributable to more favourable Jt-Ji interactions. Stability is further enhanced by using nitrated fluorophores. Fluorescent labelling of ODNs using oxyamino modified fluorescein has been reported by the incorporation into DNA of aldehyde functions. The aldehyde function was attached either at the 5 -end via a phosphate linker or internally via 8-mercaptobutanal. Reduction of the resulting oxime was not necessary. 

The conversion of naphthalene to 2-naphthoic acids by irradiation with carbon dioxide and electron donors (e.g. amines or dimethoxybenzene) has been further investigated and the quantum yields of the reaction measured for different solvents and donors. Electron transfer also occurs in the photochemical phosphonation of naphthalene and phenanthrene achieved by irradiation with trialkyl-phosphites and electron acceptors such as 1,3-dicyanobenzene. The photonitration of phenol in aqueous solutions of nitrate ion has been reported and phenols have been prepared by irradiation of substituted benzenes with the aromatic N-oxide (132). ... 

If the cationic intermediates for a substitution are close in energy, little selectivity is expected and a mixture of products is predicted. An illustration is the nitration reaction of phenanthrene, which gave five products 345 (6%), 346 (23%), 347 (7%), 348 (27%) and 349 (37%).Although substitution at C9 is preferred, a complex mixture is obtained that may be very difficult to separate. Substitution at several positions is a common occurrence for substitution reactions of polycyclic aromatic derivatives, although the product distribution is usually influenced by the nature of the catalyst and by the reaction conditions that are used. 

Structure. The structure of glaucine was arrived at by Gadamer (12) by a process of intuitive reasoning supplemented by a synthesis. Co-rytuberine dimethyl ether and glaucine were known to be isomeric, and if a relation to papaverine were admitted only two structures were available for the two alkaloids. Pschorr (13), utilizing his well-known phenanthrene synthesis, had attempted to convert papaverine into an aporphine (IV) via the nitro (II) and the amino (III) derivatives. When papaverine is nitrated it yields 6 -nitropapaverine (II), from which the methochloride... 

The mixture of octahydrophenanthrene and 1.5-2 Eq. selenium in a flask equipped with a long Pyrex tube, which functioned as an air condenser, was heated in a potassium nitrate-sodium nitrate bath at 290-320°C for 14-15 h. The dehydrogenation product was extracted with benzene the benzene extract was distilled at atmospheric pressure, and the residual was crystallized to give phenanthrene, m.p. 99.5°C. 

Both phenanthrene and anthracene have a tendency to undergo addition reactions under the conditions involved in certain electrophilic substitutions. Halogenation and nitration may proceed in part via addition intermediates ... 

Lead dioxide Lead nitrate Magnesium sulfate heptahydrate Pentaerythritol Perchloric acid Phenanthrene Picric acid Potassium alum anhydrous Potassium dichromate ... 

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