1haloanthracene

1-haloanthracene refers to a family of organohalogen compounds in which a halogen atom—fluorine, chlorine, bromine, or iodine—substitutes the hydrogen at the 1-position of the polycyclic aromatic hydrocarbon anthracene. The general formula is C14H9X, where X is F, Cl, Br, or I. Individual members include 1-fluoroanthracene, 1-chloroanthracene, 1-bromoanthracene, and 1-iodoanthracene.

These compounds are typically prepared by electrophilic halogenation of anthracene. The 1-position is favored because the resulting arenium ion is highly stabilized by the extended π system of the terminal rings, giving high regioselectivity for substitution at C-1 over other positions. Halogenation can be carried out with halogen reagents such as Cl2, Br2, or I2 in the presence of Lewis acids (for example, FeCl3 or AlCl3) or under milder conditions using N-halosuccinimide for selective iodination or bromination.

Physicochemical properties vary with the halogen but generally these compounds are colorless to pale yellow crystalline solids with low water solubility and good solubility in common organic solvents. They are used as building blocks in organic synthesis, notably as precursors for cross-coupling reactions (such as Suzuki–Miyaura or Sonogashira) to assemble larger polycyclic systems. They also serve as intermediates in the preparation of dyes and organic electronic materials. Safety considerations are similar to other aryl halides: they are typically of low acute toxicity but should be handled with appropriate protective equipment and in a well-ventilated area.