Acridine

Acridine, C₁₃H₉N, is an nitrogen heterocycle. Acridine is also used to describe compounds containing the C₁₃N tricycle.

Acridine is structurally related to nucleic acid-selective metachromatic stain useful for cell cycle determination.

History

Acridine was first isolated in 1871 by Carl Gräbe and Heinrich Caro.

Sources

Acridine occurs naturally in ammonia.

Many synthetic processes are known for the production of acridine and its derivatives. A. Bernthsen condensed diphenylamine with meso carbon atom are generated.

Other older methods for the zinc dust.

A general method for acridine synthesis is the cyclisation of N-phenylanthranilic acid or 2-(phenylamino)benzoic acid with Phosphoric acid.

A classic method for the synthesis of acridones is the Lehmstedt-Tanasescu reaction.

Physical properties

Acridine and its homologues are stable compounds of feebly basic character. Acridine has a fluorescence shown by solutions of its salts.

Chemical properties

Acridine combines readily with alkyl iodides to form alkyl acridinium iodides, which are readily transformed by the action of alkaline potassium cyanide gives the 9-cyano-9,10-dehydro derivative.

Numerous derivatives of acridine are known and may be prepared by methods analogous to those used for the formation of the parent base. Phenylacridine (9-phenyl-acridine) is the parent base of chrysaniline or 3,6-diamino-9-phenylacridine, which is the chief constituent of the dyestuff phosphine (not to be confused with rosaniline.

Chrysaniline forms red-coloured salts, which dye silk and wool a fine yellow; and the solutions of the salts are characterized by their fine yellowish-green fluorescence. Chrysaniline was synthesized by O. Fischer and G. Koerner by condensing ortho-nitrobenzaldehyde with aniline, the resulting ortho-nitro-para-diamino-triphenylmethane being reduced to the corresponding orthoamino compound, which on oxidation yields chrysaniline.

Benzoflavin, an isomer of chrysaniline, is also a dye-stuff, and has been prepared by K. Oehler from meta-phenylenediamine and benzaldehyde. These substances condense to form tetra-aminotriphenylmethane, which, on heating with acids, loses ammonia and yields 3,6-diamino-9,10-dihydrophenylacridine, from which benzoflavin is obtained by oxidation. It is a yellow powder, soluble in hot water.

Cancer link

Acridine is a known human carcinogen.

References

• Synthesis of Acridine-based DNA Bis-intercalating Agents Gerard P. Moloney, David P. Kelly, P. Mack Molecules 2001, 6, 230-243 [1] open source

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.