Benzo phenanthrene 7,12-dimethyl

GC-MS examination of the PAH fraction of sample S2 (S2-C2) gave very similar results the total ion chromatogram is shown in Figure 5. Major constituents were phenanthrene, fluoranthene, pyrene, and methyl, dimethyl/ethylphenanthrene/anthracene. Relative abundance of some C2-alkylphenanthrenes/anthracenes were higher in this sample than in S1-C2. Smaller quantities of benzo[ghi]fluoranthene, chrysene, benzo[ajanthracene, tripheny-lene, benzo[b,j, k]fluoranthenes, and benzo[e aJpyrenes and were characterized by MS. In addition, most compounds listed in Table 1 were also detected in this sample. 

With azines the situation is varied. In the radical cations of pyridine and diazines the semi-occupied orbital is largely confined to the nn orbital(s) (see Scheme 2, structure 2), while the radical cation is of the n type with monoazanaphthalenes, -phenanthrenes and -anthracenes. The situation might change with substitution. As an example, alkylpyridine radical cations are of the n type, like the parent compound, whereas for the 2,5-dimethyl, 2-chloro, and 2-bromo derivatives the structure is of the n type [13]. Likewise, with benzo[c]cinnoline the parent compound and its alkyl derivatives give an n radical cation, but with some dimethoxy derivatives a n structure is found [14] and a switch from n to 7t structure occurs also in passing from 1,2,4,5-tetrazine to its 3,6-diamino derivatives [15]. 

Thus cyclopropabenzene (61a) can be obtained in 45% yield from flash-vacuum pyrolysis of the Diels-Alder adduct 60a formed from l,6-methano[10]annulene (59a) and dimethyl acetylenedicarboxylate. In like manner the benzo analogue 59b provides cyclopropa[a]naphthalene (83%) and the dibenzo derivative 59c gives cyclopropa[/]phenanthrene. Whereas 61a and its linear naphtho[h] analogue are stable entities, 61b suffers explosive decomposition on melting and 61c decomposes at temperatures in excess of — 70° C. 

In thermolysing (93) one observes, by the evolution of dimethylamine, the first cyclization step at 160°, no doubt to the intermediate phenanthrene (94), clearly differentiated from the second one at 220°. The latter cyclization leads like the above (89) to a (1 Immixture (90%) of two isomeric dinitriles, the 2,11-dimethyl-benzo(c)phenanthrene-4,9-dicarbonitrile (95) and the 2,9-dimethylbenzo(a)-anthracene-4,11-dicarbonitrile (96), mp. 312—313°. 

The parent compound (1) was discovered in 1891 by Tauber, who called it diphenyleneazone, and later phenazone. Unfortunately, the latter name was at one time also used for 2,3-dimethyl-l-phenylpyrazol-5-one (anti-pyrine). More recently 1 has been called 3,4-benzocinnoline and now benzo-[c]cinnoline, using Chemical Abstracts nomenclature. The numbering shown is that currently used Beilstein s Handbuch employed numbering analogous to that used for phenanthrene. 

In detail, several alkylated and nonalkylated polycyclic aromatic compounds (PAHs) were detected and dominated by acenaphthene with a maximum concentration of 24 pg/L in sample B. Total concentrations of methyl- and dimethylnaphthalenes reached 5.1 pg/L and 24 pg/L, respectively. Tricyclic aromatic compounds and oxygenated PAH species were detected comprising e.g. phenanthrene, 9H-fluorenone and acenaphthenone. Methylated and dimethylated benzo(b)thiophenes as well as dibenzothiophene were also present. 

Abbreviations PAH, polycyclic aromatic hydrocarbon DE, diol epoxide PAHDE, polycyclic aromatic hydrocarbon diol epoxide PAHTC, polycyclic aromatic hydrocarbon triol carbocation TC, triol carbocation BaP, benzo[a]pyrene BeP, benzo[e]pyrene BA, benz[a]anthracene DBA, dibenz[a,h]anthracene BcPh, benzo[c)phenanthrene Ch, chrysene MCh, methylchrysene MBA, 7-methyl benz[a]anthracene DMBA, 7,12-dimethyl benz[a]anthracene EBA, 7-ethyl benz[a]anthracene DB(a,l)P, dibenzo[a,l]pyrene MSCR, mechanism-based structure-carcinogenicity relationship PMO, Perturbational molecular orbital method dA, deoxyadenosine dC, deoxycytosine dG, deoxyguanosine MOS, monoxygenase enzyme system EH, epoxide hydrolase enzyme system N2(G), exocyclic nitrogen of guanine C, electrophilic centre of PAHTC K, intercalation constant CD, circular dichroism LD, linear dichroism. 

Analogues of Anthracene and Phenanthrene.—The tandem-directed metalla-tion reaction between thiophen-3-aldehyde and thiophen-3-carboxylic acid diethylamide has been found to be a very useful method for the synthesis of thiophen analogues of anthraquinones. A detailed procedure for the synthesis of benzo[l,2-6 4,5-f)]dithiophen has been published. The reaction of l-(2-naphthyl)-5,5-dimethyl-3-oxocyclohexene with sulphur gave (168). ... 

Both kinds of programs will miss any stereoisomers whose existence cannot formally be traced to the presence of stereocenters or stereogenic double bonds or to rotation about rotatable single bonds. Thus, the chiraUty and therefore the existence of enantiomers for e.g. [2,2]paracyclophanecarboxylic acid A, 1,12-dimethyl-benzo[c]phenanthrene B, and ( [-cyclooctene C (Figure 4.1), as well as for chiral fullerenes such as C76 cannot be detected by any of the current programs due to then-conceptual limitations. 

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