Acridine-9-carboxylic acid substituted

Alkyl radicals for such reactions are available from many sources such as acyl peroxides, alkyl hydroperoxides, particularly by the oxidative decarboxylation of carboxylic acids using peroxy-disulfate catalyzed by silver. Pyridine and various substituted pyridines have been alkylated in the 2-position in high yield by these methods. Quinoline similarly reacts in the 2-, isoquinoline in the 1-, and acridine in the 9-position. Pyrazine and quinoxaline also give high yields of 2-substituted alkyl derivatives <74AHC(16)123). 

In the Bernthsen synthesis, diphenylamine 61 and carboxylic acids form 9-substituted acridines 62 (Scheme 31). 

Subsequent investigations have reinforced earlier evidence for the wide occurrence of hydrogen bonding of azines. Bonding of all the monocyclic azines,many substituted azines, and azinones with water, alcohols, and dilute acids has been studied by electronic absorption spectra and the variation of the effect with changes in the position of the substituent noted. Quinolines and acridines with chloroform, alcohols, phenols, carboxylic acids, aniline, and pyrrole show the influence of hydrogen bonding on... 

Fig. 22. Conversion via the acid chloride of a substituted acridine-9-carboxylic acid into an ester...

Diphenylamine reacts with carboxylic acids in the presence of Lewis acids (e.g. AICI3, ZnCl2) forming 9-substituted acridines 20 (Bernthsen synthesis) ... 

The aromatic spacer group of the model receptors prevent the formation of intramolecular hydrogen bonds between the opposing carboxyls yet these functions are ideally positioned for intermolecular hydrogen bonds of the sort indicated in 32. The acridine derivatives do indeed form stoichiometric complexes with oxalic, malonic (and C-substituted malonic acids) as well as maleic and phthalic acids, Fumaric, succinic or glutaric acids did not form such complexes. Though protonation appears to be a necessary element in the recognition of these diacids, the receptor has more to... 

Dehydroquinic acid, shikimic acid, and chorismic acid are carboxylated compounds containing a six-membered carbocyclic ring with one or two double bonds (Fig. 143). The secondary products derived from these substances either still contain the ring and the C -side chain of the acids (see the structure of the benzoic acid derivatives, of anthranilic and 3-hydroxyanthranilic esters, D 8, D 8.2, D 8.4 and D 8.4.1) or have additional rings (see the formulae of naphthoquinones and anthraquinones, D 8.1, of quinoline, acridine, and benzodiazepine alkaloids, D 8.3.2). The carbon skeletons may be substituted by isoprenoid side chains (see the structure of ubiquinones, D 8.3) and may carry different functional groups, e.g., hydroxy, carboxy, methoxy, and amino groups. 

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