Phenanthrene, alkylation

There are two major routes to phenanthrene, both of which can be used to prepare substituted derivatives. In the Haworth synthesis (Scheme 12.11), reaction of naphthalene with succinic anhydride yields an oxobut-anoic acid which is reduced under Clemmensen conditions to the butanoic acid. Cyclization in sulfuric acid and reduction of the resulting ketone is followed by dehydrogenation over palladium-on-carbon to phenanthrene. Alkyl or aryl derivatives can be obtained by treatment of the intermediate ketone with a Grignard reagent prior to dehydration and oxidation. 

The acid 19 has been dimerized, although in low yield, in the course of a perhydro-phenanthrene synthesis [141]. When the oxidation potential of the double bond is sufficiently lowered by alkyl substituents, lactone formation by oxidation of the couble bond rather than of the carboxyl group occurs (Eq. 7) [142] (see also chap. 15). 

The reaction has been applied to nonheterocyclic aromatic compounds Benzene, naphthalene, and phenanthrene have been alkylated with alkyllithium reagents, though the usual reaction with these reagents is 12-20, and Grignard reagents have been used to alkylate naphthalene. The addition-elimination mechanism apparently applies in these cases too. A protected form of benzaldehyde (protected as the benzyl imine) has been similarly alkylated at the ortho position with butyl-lithium. ... 

The latter reagent also methylates certain heterocyclic compounds (e.g., quinoline) and certain fused aromatic compounds (e.g., anthracene, phenanthrene). The reactions with the sulfur carbanions are especially useful, since none of these substrates can be methylated by the Friedel-Crafts procedure (11-12). It has been reported that aromatic nitro compounds can also be alkylated, not only with methyl but with other alkyl and substituted alkyl groups as well, in ortho and para positions, by treatment with an alkyllithium compound (or, with lower yields, a Grignard reagent), followed by an oxidizing agent such as Bra or DDQ (P- 1511). 

It has become clear that benzoate occupies a central position in the anaerobic degradation of both phenols and alkylated arenes such as toluene and xylenes, and that carboxylation, hydroxylation, and reductive dehydroxylation are important reactions for phenols that are discussed in Part 4 of this chapter. The simplest examples include alkylated benzenes, products from the carboxylation of napthalene and phenanthrene (Zhang and Young 1997), the decarboxylation of o-, m-, and p-phthalate under denitrifying conditions (Nozawa and Maruyama 1988), and the metabolism of phenols and anilines by carboxylation. Further illustrative examples include the following ... 

The redox system consists of pyrene or 9,10-phenanthrene quinone as oxidant and an alkyl ester of 3,3, 3"-nitrilopropionic acid as reductant.121 This system deactivates oxidation by bisimidazole when irradiated at 380-550nm, since the quinone is reduced to hydroquinone and thus stabilizing the previously generated dye image.122,123... 

In agreement with this, the analysis of the products forming during the alkylation over MCM-22 samples at different reaction time showed that about 80-90 wt. % of the recovered material is adsorbed on the external surface (phenol, o-TBP and p-TBP), whereas only about 10-20 wt.% is formed inside the zeolite ( coke constituted by p-TBP, naphthalenes, 9,10-dihydro-phenanthrene and acenaphthylene). Coke molecules could be formed in both supercages and sinusoidal channels. However, in the large supercages they would be converted into bulkier compounds, which is not the case. Therefore they are most likely located in the sinusoidal channels. 

Fig. 16. CEC separation of naphthalene (1), fluorene (2), phenanthrene (3), anthracene (4), pyrene (5),triphenylene (6),andbenzo(a)pyrene (7) using capillary filled with CIO alkyl substituted polyallylamine. (Reprinted with permission from [86]. Copyright 1997 Elsevier). Conditions capillary 50 pm i.d., 48 cm total length, 33 cm active length, field strength 400 V/cm, carrier concentration 20 mg/ml, mobile phase 60 40 methanol-20 mmol/1 borate buffer pH=9.3...

Addition of carbenes to Jt-electron excessive aromatic compounds, or those which possess a high degree of bond fixation, is well established. Dihalocarbenes react with naphthalenes with ring expansion to produce benztropylium systems (Scheme 7.8). Loss of hydrogen halide from the initially formed product leads to an alkene which reacts with a second equivalent of the carbene to yield the spirocyclopropyl derivatives in high yield (>95%) [14, 50]. Insertion into the alkyl side chain (see Section 7.2) also occurs, but to a lesser extent [14]. Not unexpectedly, dichlorocarbene adds to phenanthrenes across the 9,10-bond [9, 10, 14], but it is remarkable that the three possible isomeric spiro compounds could be isolated (in an overall yield of 0.05% ) from the corresponding reaction with toluene [14]. 

These conclusions were not applicable when sediment was the source of hydrocarbons. McCain et al. (5) studied the bioavailability of petroleum in sediment to English sole (Parophrys vetu-lus). Sediments rich in alkylated and non-alkylated benzenes and naphthalenes, together with fluorene and phenanthrene, were employed. After 11 days of exposure, samples of skin, muscle, and liver were examined. Fluorene and phenanthrene were not accumulated in the test fish however, significant concentrations of 1-methyl naphthalene, 2-methyl naphthalene, 2,6-dimethyl naphthalene and 1,2,3,4-tetramethylbenzene, were found in skin and liver (Table II) 1-methyl naphthalene and 2-methyl naphthalene were the major components of muscle. In each tissue examined, 1-methyl-naphthalene was the major component 1,2,3,4-tetramethylbenzene occurred in relatively low concentrations in skin and muscle in comparison to naphthalenes containing one and two alkyl groups. 

These data imply that aromatic hydrocarbons incorporated into sediments are not preferentially accumulated in relation to increased alkyl substitution, as shown with dietary and seawater exposures. Moreover, the apparent lack of accumulation of the fluorene and phenanthrene suggests that unsubstituted aromatic hydrocarbons having more than two benzenoid rings may not be readily sequestered by fish exposed to petroleum-impregnated sediment. These differences are presumably related, at least in part, to physico-chemical interactions of aromatic hydrocarbons with sediment matrices that regulate their bioavailability. 

Thomas et al. (43) showed that phenanthrene is actively metabolized in salmonTds and Lee et al. (41) have shown that benzo[a]pyrene is biodegraded in three species of marine fish. Varanasi et al. (VI ) demonstrated for the first time that the skin of fish exposed to aromatic hydrocarbons via either force-feeding, intraperitoneal injection, or in flowing seawater accumulate substantial concentrations of metabolic products. This is of particular interest since studies of mammalian systems have shown that some alkyl naphthalenes can be accelerators of skin carcinogenesis (32). Varanasi et al. (11) also demonstrated that the mucus of rainFow trout exposed to radiolabeled naphthalene... 

The alkyl-substituent pattern for some PAHs series (e.g., alkylnaphthalenes, phenanthrene/anthracene, pyrene/fluoranthene, m/z 228 and m/z 252) are shown in Figs. 6-9, respectively. The parent PAHs and their alkylated homologs are determined in GC-MS data by monitoring their corresponding molecular weights. For example, for the naphthalene series the ions at m/z 128,142 methyl-naphthalenes, 156 C2-naphthalenes, 170 C3-naphthalenes, and 184 C4-naphtha-lenes are monitored (Fig. 6). The GC elution orders of the C2-naphthalene and C3-naphthalene isomers have been reported [144,145]. 

Fig. 7a-e. Alkyl-substituted phenanthrene series (GC-MS key ions mlz 178,192,206,220, and 234) from a bottom ash sample from a coal fired power plant... 

Figure 3.3 SPMD-water partition coefficients (ml mL units) as a function of log Kqw for PAHs—filled circles Huckins et al. (1999), filled triangles Huckins et al. (2004) phenanthrene, PCB 52, and p,p -DDE—open triangles Huckins et al. (2002a) chlorobenzenes, PAHs, and PCBs—squares Booij et al. (2003a) pesticides—filled diamonds Sabaliunas and Sodergren (1997) and HCHs—open diamonds Vrana and Schiiurmann (2002). Additional kjw data were calculated for PCBs (asterisks) and alkylated benzenes (crosses) using the fCmw data from Lefkovitz et al. (1996) and Reynolds et al. (1990), and the data from Chiou (1985).

Lund and coworkers [131] pioneered the use of aromatic anion radicals as mediators in a study of the catalytic reduction of bromobenzene by the electrogenerated anion radical of chrysene. Other early investigations involved the catalytic reduction of 1-bromo- and 1-chlorobutane by the anion radicals of trans-stilhene and anthracene [132], of 1-chlorohexane and 6-chloro-l-hexene by the naphthalene anion radical [133], and of 1-chlorooctane by the phenanthrene anion radical [134]. Simonet and coworkers [135] pointed out that a catalytically formed alkyl radical can react with an aromatic anion radical to form an alkylated aromatic hydrocarbon. Additional, comparatively recent work has centered on electron transfer between aromatic anion radicals and l,2-dichloro-l,2-diphenylethane [136], on reductive coupling of tert-butyl bromide with azobenzene, quinoxaline, and anthracene [137], and on the reactions of aromatic anion radicals with substituted benzyl chlorides [138], with... 

The Jackson laboratory of the du Pont Company soon became interested in the catalytic power of hydrogen fluoride. The results of its work are recorded in three excellent papers. Using acrolein as the alkylating agent and hydrogen fluoride as the catalyst, peri syntheses have been performed (Calcott et al, 32), both those that are catalyzed by sulfuric acid and others that are not. By appropriate condensation, dehydration, and reduction, perylene was obtained from phenanthrene... 

Dienolate alkylations have been applied successfully in syntheses of steroids and terpenoids. A highly diastereoselective application81 is the preparation of the phenanthrene derivative 35. 

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