Regiochemistry theory in acetyl nitrate and nitric acid nitrations

Abstract

Although the structures of the reaction products obtained with different nitrating reagents are well known, a complete theory regarding the regiochemistry is missing. Even though the functional groups have been grouped according the exerted orientation in electrophilic substitution reactions, in many cases there is no explanation about the preponderance of one of the expected isomers.
On the other hand, the preferent ortho orientation of acetyl nitrate in nitration reactions is well known. However, a causal explanation of this phenomenon has not been provided.
In this communication a regiochemistry theory in acetanilide nitration is presented, both when sulfonitric mixture or when acetyl nitrate are used. This theory was confirmed by comparison to the experimental results obtained when these reactions were run with toluene or with anisole.