Aromatic substitution reactions halogenation

Given the reactants, write the structures of the main organic products of the common electrophilic aromatic substitution reactions (halogenation, nitration, sulfonation, alkylation, and acylation). 

Many of the common electrophilic aromatic substitution reactions can be conducted on indole. CompHcations normally arise either because of excessive reactivity or the relative instabiUty of the substitution product. This is the case with halogenation. 

The hydroxyl group is a strongly activating, ortho- and para-directing substituent in electrophilic aromatic substitution reactions (Section 16.4). As a result, phenols are highly reactive substrates for electrophilic halogenation, nitration, sulfonation, and lTiedel-Crafts reactions. 

Unlike benzene, pyridine undergoes electrophilic aromatic substitution reactions with great difficulty. Halogenation can be carried out under drastic conditions, but nitration occurs in very low yield, and Friedel-Crafts reactions are not successful. Reactions usually give the 3-substituted product. 

Sec. 16.1, 16.2) from anenes by electrophilic aromatic substitution with halogen (Sec. 24.8) from arenediazonium salts by reaction with cuprous halides (Sandmeyer... 

Polymers aren t really that different from other o antc molecules. They re much larger, of course, but their chemistry Is similar to that of analc ous small molecules. Thus, the alkane chains of polyethylene undergo radical-initiated halogenation the aromatic rings of pelyalyrone undergo typical electrophilic aromatic substitution reactions and the amide linkages of a nylon are hydrolysed by (wise. 

Although the preparation of aryl cyanides from the corresponding halogen compounds is described by the very simple equation (8), the process does not correspond to a simple aromatic substitution reaction. In a series of comprehensive articles various aspects of this transformation are discussed. An excellent review, written by Ellis and Romney-Alexander, should be mentioned in particular, as it provides the literature leading into the modem status of the field. 

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