Phenanthrene-9-carboxylic phenanthrenes

An important extension of this carboxylation strategy has recently been suggested by Zhang and Young (1997) who studied the degradation of two polycyclic aromatic hydrocarbons (PAHs), naphthalene and phenanthrene, in a sulfate-reducing sediment. The naphthalene was found to be converted to 2-naphthoic acid and the phenanthrene to phenanthrene carboxylic acid (see below). Further degradation to C02 was rapid after the presumptive initial carboxylation. Possibly carbon dioxide derivatives can be made so electrophilic by enzymatic interactions (shown... 

C,II7CI2F20 38492-84-1) see Halofantrine 13 dichloro-6-(trifluoromethyl)-9-phenanthrene-carboxylic acid... 

Abietic Acid or Sylvie Acid (l,2,3,4,4a,4b,5, 6,10,10a-Decahydro-7-isopropyl-l,4a-dimethyl-1-phenanthrene-carboxylic Acid), C,Hj,COOH,... 

In contrast to the preferred meta mode of intramolecular photoaddition of 5-phenyl-l-pentenes, where the alkene and benzene groups are separated by three atoms, irradiation of the styrene (64) yields a single stereoisomer of the ortho adduct (65). In (64), not only are the reacting units separated by 4 atoms, but also it is the styrene rather than the benzene which is excited. Comparable photoreactivity is seen for phenanthrene-styrene systems such as (66) which yield 2+2 adducts (67) along with products derived from competing Paterno-Btichi reaction of the ester carbonyl with the alkene side chain. The photochemical cycloaddition also proceeds in an intermolecular fashion between the ester of 9-phenanthrene carboxylic acid and para-methoxy-0-methylstyrene. The mechanism of this reaction is shown to involve addition of the styrene to the singlet excited state of the phenanthrene derivative. °... 

The AT-methylanonaine was obtainable by reaction with forniic acid and formaldehyde, and Hofmann degradation via A-methylanonaine methiodide (m.p. 217°) gave a methine base (m.p. 87-90°) and a vinyl-phenanthrene (m.p. 87°) which on oxidation generated a phenanthrene-carboxylic acid (m.p. 240°) which could be decarboxylated to what was evidently 3,4-methylenedioxyphenanthrene (m.p. of picrate, 168°). 

With compounds such as methyl-lO-hydroxy-9-phenanthrene carboxylate [30], the increased degree of fixation of the ring double bonds results in stronger chelation, so that the frequency shift is increased to about 75 cm". As in the case of the corresponding ketones, the frequency shifts of chelated esters have been used to measure double-bond character in the indane series [55]. 

Hydrogen and sodium do not react at room temperature, but at 200—350°C sodium hydride is formed (24,25). The reaction with bulk sodium is slow because of the limited surface available for reaction, but dispersions in hydrocarbons and high surface sodium react more rapidly (7). For the latter, reaction is further accelerated by surface-active agents such as sodium anthracene-9-carboxylate and sodium phenanthrene-9-carboxylate (26—28). 

Elimination of sulfur from methyl dibenzo[/),/]thiepin-10-carboxylatcs 15 (R2 = Me) can be achieved in moderate yields (39-55%) upon refluxing in diethyl phthalate in the presence of copper bronze.60 For the dibenzo[A,/]thiepin-10-carboxylic acids 15 (R2 = H), the loss of sulfur is accompanied by decarboxylation. Thus, treatment of these acids with copper bronze in refluxing quinoline for four hours gives the corresponding phenanthrenes 16 (R3 = H) in moderate yield (50%). However, the exposure time to high temperatures influences the product formation. Thus, the decarboxyiated dibenzothiepins are obtained after refluxing for only five minutes.60... 

Ethyl 1 /T-azepine-l-carboxylate (1) and l,3-diphenyl-2/7-cyclopenta[/]phenanthren-2-one (26) (phencyclone) in refluxing benzene undergo a rapid peri- and regioselective cycloaddition to give the [4 + 2] 7t-e rfn-adduct 28 and not, as was first proposed, a [6 + 2] 7r-adduct.264 Subsequently, however, it was found that at room temperature a [2 + 4] 7r-cw/<>-adduct 27 is formed which readily undergoes a Cope rearrangement to the [4 + 2] endo,anti-adduct 28. 

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). 

Pure cultures growing anaerobically with catechol and sulfate were isolated,and the carboxylation of catechol was proposed to be the initial reaction of anaerobic catechol degradation by Desulfobacterium sp. strain Cat2. Zhang and Young" proposed that the initial key reaction for anaerobic degradation of naphthalene and phenanthrene was also carboxylation. 

C[bicarbonate] and mass spectrometry were used to demonstrate the formation of carboxylic acids during the sulfidogenic mineralization of naphthalene and phenanthrene (Zhang and Young 1997). 

Zhang X, LY Young (1997) Carboxylation as an initial reaction in the anaerobic metabolism of naphthalene and phenanthrene by sulfidogenic consortia. Appl Environ Microbiol 63 4759-4764. 

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 ... 

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