Acridine-type nitrogen

The oxidation of chars prepared from nitrogen-containing precursors has been investigated. Chars produced from the nitrogen-containing compounds acridine and phenanthridine were oxidized at atmospheric pressure at temperatures of 773-873 K. The relative rates of nitrogen and carbon release and the formation of NO have been determined in relation to char nitrogen content and precursor type. 

The pyridine ring is fused at bond a of the acridine. Depending on the position of the nitrogen in the fused pyridine ring, four different types of pyrido[fl]acridines are possible. 

A heteroatom in the aromatic ring may be thought of as a special kind of substituent. Two types of heteroatoms may be distinguished. If the heteroatom contributes one 7i-electron to the aromatic system, it will be bonded to the adjacent atoms, very much like aromatic carbon. It will exert its effect on the electronic structure of the molecule by virtue of its possession of nonbonded electron pairs and by its ability, relative to that of aromatic carbon, to attract 7i-electrons. Nitrogen, as it occurs in pyridine, quinoline, isoquinoline, and acridine, is the only common member of this class of heteroatoms and will hereafter be referred to as pyridinic nitrogen. 

Nitrogen analogues (5) of o-xylylenes are produced as transient intermediates in the flash pyrolysis of o-amino-benzyl alcohols (4). They do not undergo ring-closure to benzazetines but cyclize to acridines via dihydroacridines. Possibly the same type of imine methide is involved in the thermal and photochemical extrusion of sulphur dioxide from the cyclic sulphones (6), which in this case does give the benzazetine. ... 

ICR-170 is an acridine with one nitrogen mustard group. It has been employed as an antitumor agent (Creech et al., 1972). In our repair assay, this agent induced repair events similar although not identical to those induced by jV-acetoxy-AAF (Fig. 10). ICR-170 differed from jV-acetoxy-AAF in that the size of the repaired regions with ICR-170 was smaller (approximately ten BrUra residues) than those with jV-acetoxy-AAF (approximately 25 BrUra residues). Nevertheless, ICR-170 clearly induces UV-type repair in normal cells and, like jV-acetoxy-AAF, defective repair in XP cells (see Section VI). 

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