The word cine comes from the Latin word which means next or near. Cine substitution reactions occur in the aromatic ring which has electron-withdrawing groups that stabilize the intermediate state of the reaction. In cine substitution reaction, the entering group takes up a position next (i.e. adjacent) to that occupied by the leaving group.
Cine substitution reaction involves the formation of a benzyne intermediate or other strained cyclic intermediates. The benzyne mechanism is a good example of how cine substitution occurs.
The Von Richter reaction is an example of a cine substitution reaction in which aromatic nitro compounds react with potassium cyanide in aqueous ethanol to produce a cine substituted product by a carboxyl group.
Cine Substitution in Chlorobenzene
Mechanism