Pd-Catalyzed New Dinitration Reaction Of Secondary And Tertiary Aromatic Amines

This paper mainly introduces the Pd(OAc)2 as a catalyst to achieve dinitration compounds of secondary aromatic amines and tertiary aromatic amines.2,4-dinitro-secondary aromatic amine,2,4-dinitro-tertiary aromatic amines are the intermediates which are used in the synthesis of high explosives and azo-dyes. Vertical well known, mixed acid system (H2SO4, HNO3) as a traditional nitrification system are applied to the synthesis of the nitration of aromatic compounds which have been widely recognized and used. However, the mixed acid system was used in nitration reaction of secondary aromatic amines and tertiary aromatic amines, especially dinitration, was limited rightly. On the one hand, mixed acid will react with aniline compounds to generate salt directly; on the other hand, mixed acid systems need some strong oxidizing acids, which will oxidize aniline compounds.Therefore, how to develop an environmentally friendly, efficient and mild conditions method about dinitration reaction of secondary aromatic amines and tertiary aromatic amines has great potential research value and significance.In this report, we select secondary aromatic amines and tertiary aromatic amines as substrates and then investigate the dinitration reaction of them. The main experiment investigated the impact of catalyst, temperature, solvent for the reaction. At last, we established Bi(NO3)3·5H2O as the nitrating agent, Pd(OAc)2 as the catalyst, TFE/TFA (3/1) as the mixed solvent, and reacted at 90℃ for 24 h under Ar. Using the one-pot method to obtain dintration compounds of secondary aromatic amines and aromatic tertiary amines which have different substituents. Experimental results indicated that secondary aromatic amines could obtain the corresponding dinitro-compounds efficiently, and the results of tertiary aromatic amines were complicated relatively.