Acridine, C13H9N, is an organic compound and a nitrogen heterocycle. Acridine is also used to describe compounds containing the C13N tricycle.
Acridine is structurally related to anthracene with one of the central CH groups is replaced by nitrogen. Acridine, a colorless solid, was first isolated from coal tar. It is a raw material used for the production of dyes and some valuable drugs. Many acridines, such as proflavine, also have antiseptic properties. Acridine and related derivatives bind to DNA and RNA due to their abilities to intercalate. Acridine orange (3,6-dimethylaminoacridine) is a nucleic acid-selective metachromatic stain useful for cell cycle determination. Acridarsine is formally derived from acridine by replacing the nitrogen atom with one of arsenic, and acridophosphine by replacing it with one of phosphorus.
Acridine was first isolated in 1871 by Carl Gräbe and Heinrich Caro.
Acridine occurs naturally in coal tar. It is separated from coal tar by extracting with dilute sulfuric acid; addition of potassium dichromate to this solution precipitates acridine bichromate. The bichromate is decomposed using ammonia.
Many synthetic processes are known for the production of acridine and its derivatives. A. Bernthsen condensed diphenylamine with carboxylic acids, in the presence of zinc chloride in the Bernthsen acridine synthesis. With formic acid as the carboxylic acid the reaction yields acridine itself, and with the higher homologues the derivatives substituted at the meso carbon atom are generated.
Other older methods for the organic synthesis of acridines include condensing diphenylamine with chloroform in the presence of aluminium chloride, by passing the vapours of orthoaminodiphenylmethane over heated litharge, by heating salicylic aldehyde with aniline and zinc chloride to 260 °C or by distilling acridone (9-position a carbonyl group) over zinc dust.
Full article ▸