(i) Sandmeyer’s Reaction - Benzene diazonium chloride is converted to chlorobenzene, bromobenzene, cyanobenzene on treatment with CuCl/HCl, CuBr/HBr and CuCN/KCN, respectively.
(ii) Finkelstein Reaction - Chloroalkanes or bromoalkanes are converted into corresponding iodoalkanes by treating with sodium iodide dissolved in acetone.
(iii) Wurtz Reaction - Alkyl halides react with metallic sodium in the presence of dry ether to form alkanes. This reaction is used for the preparation of higher alkanes.
(iv) Wurtz-Fittig Reaction - Aryl halides when treated with alkyl halide and sodium in dry ether give alkylbenzenes.
(v) Fittig Reaction - In this reaction two molecules of haloarene combine with metallic sodium in the presence of dry ether to give diphenyl or biphenyl.
(vi) Friedel–Crafts Alkylation - Benzene and other aromatic compounds react with alkyl halides in the presence of anhydrous AlCl3 to form alkyl benzene.
(vii) Friedel–Crafts Acylation - Benzene and other aromatic compounds react with acyl halides in the presence of anhydrous AlCl3 to form acyl benzene.
(viii) Dow’s Process - When chlorobenzene is treated with an aqueous solution of NaOH at 623 K, 300 atm pressure sodium phenoxide is formed which on acidification gives phenol.
(ix) Hunsdiecker’s Reaction - Bromoalkanes are obtained by this method by refluxing silver salts of fatty acids with Br2 in CCl4. This method can be used to decrease the number of carbon atoms.
(x) Gatterman’s Reaction - The reaction of diazonium salts with ‘Cu’ powder in the presence of corresponding halogen acids is known as Gatterman’s reaction.
(xi) Iodoform Reaction - Iodoform is prepared by the action of iodine and alkali on ethyl alcohol or acetone.
