Studies on the selective synthesis of N-monoalkyl aromatic amines

The intermediate Schiff base was detected by GC¯MS in the reductive alkylation of nitro aromatic compounds catalysed by Raney nickel, supporting the proposed reaction mechanism. The influence of substituents and alkylating agents-alcohols on the reaction were studied and the results showed that both the position and properties of the substituents and the structures of the alcohols used have a significant effect on the N-alkylation. Steric hindrance is the main factor which inhibits N-alkylation and causes side reactions. High yields of Nmonoalkyl arylamines were obtained with nitro compounds having para- or metasubstituents and with straight chain alcohols, except for methanol.