HALOARENE

Haloarene (aryl halide)

Preparation

1. By halogenation of benzene
Benzene on halogenations is the presence of FeCl3 or anhy. AlCl3 gives halo benzene.

2. For phenol

3. From diazonium salt
Note: When aniline is treated with NaNO2 and conc. HCl at cold condition, diazonium salt is formed. This reaction is called diazotization reaction.

When diazonium salt is treated with cuprous halide in presence of HX, halo benzene is formed. This reaction is called sandmeyer reaction.

Physical properties

1. It is colourless volatile liquid with odour like almond.
2. It is insoluble in water but soluble in ether, benzene etc.
3. It is heavier than water.

Chemical properties

1. Nucleophilic substitution reaction
i. With aqueous NaOH