Acridine-9-oxide, nitration

The nitration of acridine (9 R = H) in sulfuric acid is an unsatisfactory reaction in that the mixed isomers produced are difficult to separate. The main product is 2-nitroacridine (9 R = N02) the order of reactivity being 2>4>1>3 and product ratio 130 25 5 1 respectively (B-66MI20600). Acridine AT-oxide, however, undergoes nitration at 0°C to produce 9-nitroacridine AAoxide (10) (60JCS3367). 

The nitrations of a wide range of substituted quinoline N-oxides under various conditions [82HC(382)447] show the usual pattern of substituent effects superimposed upon the pattern resulting from the use of nitric acid/sulfuric acid at low temperature (5,8-positions), weaker mixtures of these acids at high temperature (4-position), or acyl nitrates (3-position). Nitration of acridine N-oxide by nitric acid/sulfuric acid occurs in the 5-position (60JCS3367). 

Acridine, halogenation, 59, 295 Acridine A-oxide, halogenation, 59, 295 Acridine, 9-benzyl-, nitration, 58, 251 Acridine, 9-phenyl-, nitration, 58, 251 Acridin-9(10//)-ones, see Acridones Acridizinium ion, see... 

Reactions of dibenzopyridines show analogies with pyridine, quinoline and isoquinoline. Acridine and phenanthridine are A-protonated by strong protic acids, iV-alkylated by alkyl halides and A-oxidized by peroxy acids. Electrophilic substitutions of acridine often result in disubstitution at the 2- and 7-positions (e.g. nitration giving 3), whereas those of phenanthridine occur at different positions (e.g. nitration mainly at the 1- and 10-position yielding 4 and 5) ... 

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