Polyhalogenonitrobenzenes and derived compounds. Part 2. Reactions of 1,2,3,4-tetrachloro-5,6-dinitrobenzene with aliphatic amines under phase-transfer conditions

Abstract

The reactions of acyclic and cyclic aliphatic amines with 1,2,3,4-tetrachIoro-5,6-dinitrobenzene have been investigated under phase-transfer conditions (toluene-water in the presence of Aliquat 336). In comparison with the corresponding reactions in toluene alone as solvent, overall reactivity was increased, and there was an enhanced preference for chlorine rather than nitro-group displacement. An explanation for this is advanced.We have previously investigated the relationship between amine structure and the nature of the products of the reaction between 1,2,3,4-tetrachloro-5,6-dinitrobemne (TCDNB) and amines in toluene. Primary amines displace a nitro group giving a product of structure (l), whereas acyclic secondary amines tend to replace a chlorine, leading to a product having structure (2). In all cases it is the chlorine ortho to a nitro group which is replaced. Cyclic secondary amines tend to give a mixture of products arising from both chlorine and nitro-group replacement. In some cases disubstituted products [(3) or (4)] were also isolated.This paper reports the results of a complementary study in