The Nitrile Coupling

The synthesis of aryl or alkyl nitriles from halides is valued in medicinal chemistry, because the nitriles themselves constitute a flexible building block that easily can be converted into carboxylic acids, amides, amines, or a variety of heterocyclic compounds [103], for example thiazoles, oxazolidones, triazoles, and tetrazoles [104]. 

The importance of the tetrazole group in medicinal chemistry is easily understood if one remembers it is the most commonly used bioisostere of the carboxyl group. 

R = alkyl, aryl alkyl, alkenyl alkyl, alkoxy alkyl 

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