Abstract:
Early research into the halogenation of aromatic compounds revealed that two types of product could be produced, depending on the conditions of the reaction. Benzene, on which the majority of the work was carried out, gave addition products C₆H₆X₆ and substitution products C₆H₅X. In the absence of light substitution occurs. This type of reaction was investigated by Burner (1) (2), Stator (3) and Knoevenagel (4) who studied the effects of a variety of catalysts including iodine, salts of aluminium, iron and antimony.
The influence of the solvent, in which the halogenation is carried out, upon the reaction was investigated by Bruner and Vorbrodt (5) and more recently by Kharasch et al (6). Their results show that the rate and type of halogenation varies with the nature of the solvent.