Aromatic Nucleophilic Substitution of Halobenzenes with Amines under High Pressure

Abstract

Abstract The nucleophilic substitution reactions of aromatic halides having electron-attracting groups on ortho or para position with various primary and secondary amines were accelerated by high pressure to give the corresponding N-substituted anilines in high yields. The bulkiness of amines affects its reactivity to lower the yields of the products. Although the secondary amines are usually less reactive than primary amines, cyclic secondary amines such as morpholine, piperidine, and pyrrolidine were found very reactive. 1,4-Diazabicyclo[2.2.2]octane and quinuclidine gave N-quaternary ammonium halides in high yields in contrast to the low reactivity of acyclic tertiary amines. Dichloro- and trichloro-nitrobenzenes also react with diethylamine, pyrrolidine, and morpholine to give mono-, di-, and trisubstitution products depending upon the amount of amine and the position of nitro group in these chlorides.