Halogenation of Benzene, Nitration of Benzene, Sulfonation of Benzene and Alkylation and Acylation of Benzene are some various chemical reactions of Benzene. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Reaction type: Radical Substitution. Water-soluble analogs for use as dyes were developed later… Reaction of Alkyl Benzenes with Halogens. Learn more about the benzene reactions at vedantu.com. Halogenation of aromatic compounds. Halogenation of the benzene rings alters the shade to bluish-green and green. the halogenation of benzene This page gives you the facts and a simple, uncluttered mechanism for the electrophilic substitution reaction between benzene and chlorine or bromine in the presence of a catalyst such as aluminium chloride or iron.

Pigment Green 7), all 16 hydrogens on the four benzo rings are replaced with chlorine. Substitution reactions.

Benzene reacts with chlorine or bromine in the presence of a catalyst, replacing one of the hydrogen atoms on the ring by a chlorine or bromine atom. This reaction works only for chlorine and bromine and is carried in the presence of a Lewis acid such as FeX 3 (laboratory method).

Aromatic compounds are subject to electrophilic halogenation: RC 6 H 5 + X 2 → HX + RC 6 H 4 X. The LibreTexts libraries are Powered by MindTouch ® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot.
Methyl groups are 2,4-directing, which means that incoming groups will tend to go into the 2 or 4 positions on the ring - assuming the methyl group is in the 1 position. Benzene is a colorless liquid that was first discovered by Michael Faraday in 1825. When treated with Br 2 or Cl 2 radical substitution of benzylic-H generates the benzyl halide and HX. The reactions happen at room temperature.

Summary. The role of the Lewis acid is to polarize the halogen-halogen bond, making the halogen molecule more electrophilic.
This is exactly the same as the reaction with benzene, except that you have to worry about where the halogen atom attaches to the ring relative to the position of the methyl group. ; The benzyl radical is quite stable so bromination will often by selective for the benzyl position. The halogenation of benzene.

The molecular formula of benzene is C6H6. In an important phthalocyanine, Monastral Fast Green G (C.I.