2-Azaanthracenes

Chemical Designations - Synonyms 10-Azaanthracene, Benzo (b) Quinoline, Dibenzo [b,e] Pyridine Chemical Formula C,3H,N. 

A large number of electron-rich polycyclic aromatic systems including anthracenes, azaanthracenes and larger homologues arenes undergo [4 - - 2]-cycloaddition with singlet... 

Figure 15 (1) UV absorption spectra of anthracene, phenazine and acridine in ethanol. (2) UV absorption spectra of anthracene, and 1- and 2-azaanthracene in ethanol (Reproduced with permission from (51JCS3199))...

ACRIDINE Dibenzo [ b,e] Pyridine, lti-Azaanthracene, Benzo(b)-Qni noline Poison, III NL NL NL ... 

Anthracene and certain other polynuclear hydrocarbons have long been known to dimerize readily on photolysis the formation of such dimers [Eq. (68)] is also the result of 1,4-addition, and is believed to involve a singlet excited state. With substituted anthracenes, the head-to-head dimer is generally formed, although there are exceptions to this rule. Dimerizations probably of a similar nature, have been reported for a number of azaanthracenes including 1-azaanthra-cene,270,271 2-azaanthracene,271 and benz[6]acridine.272 The precise structure of these dimers in uncertain. 

Table X. Moles of Azaanthracenes/Azaphenanthrenes and Their Hydrogenated Analogs at Molecular Weights 179-189 in Feed and Reactor-Sample 1.

The results in Table X reveal that hydrotreating under the reaction conditions and catalyst specified in Table I reduced the moles of azaanthracenes and azaphenanthrenes by ca. 83%. However, it is important to note that the decrease of 6.7 millimoles in reactants (mass 179) essentially equals, within the limits of data precision, the increase of 6.3 millimoles in products (masses 181 through 189). Consequently, for the given catalyst, the reaction conditions were insufficiently severe to convert intermediate products to hydrocarbons and NH. ... 

The emergence of the azafluorenone alkaloids as a sizable group and the discovery of the azaanthracenes and azahomoaporphines, all represented in Guat-teria, are very new developments. This chapter reviews these novel substances as completely as possible, discusses a small number of structurally unusual though not unprecedented compounds, and also updates the older contributions on the mainline isoquinoline alkaloids insofar as the genus Guatteria is concerned. 

Dielsiquinone (134) is the only Guatteria alkaloid known to possess the 1-azaanthracene ring system (22). This skeleton was found for the first time in the parent compound cleistopholine (154), isolated successively from the An-nonaceae Cleistopholis patens (77) and Meiogyne virgata (78), and later also from Annona cherimolia (79) and A. hayesii (80). The latter species also contains the related annopholine (155). Annona ambotay (81) is the only known... 

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