Simple Synthesis of N-Aryl-2-nitrosoanilines in the Reaction of Nitroarenes with Aniline Anion Derivatives

Abstract

Anions generated from primary arylamines react with substituted nitrobenzenes to form s H -adducts, which, under basic reaction conditions, undergo transformation to N-aryl-2-nitrosoamines. Competitive substitution of reactive halogens in the nitroarenes, which is observed in certain cases, can be controlled by the solvent selected.

2‐(Arylamino)aryliminophosphoranes from 2‐nitrodiarylamines

“…Regarding the already known iminophosphoranes 3a – c , the yields obtained in the direct reaction of the corresponding nitrosoanilines 2 were higher, although . The important procedure is, however, that according to our expectations, it opens the possibility to obtain 2‐(arylamino)aryliminophosphoranes which are unavailable from the direct reactions of corresponding 2‐nitrosoanilines when the latter are difficult or impossible to obtain by the methods described previously …”

“…The major problem in broadening its synthetic scope is availability of starting materials. Numerous of 2‐nitrosodiarylamines can be easily obtained by nucleophilic substitution of hydrogen (S N H Ar) in nitroarenes with arylamines in the presence of a strong base at low temperature . However, certain types of them could not be obtained that way.…”

Synthesis of 1-arylbenzimidazoles and dibenzo[b,e][1,4]diazepines from 2 (arylamino)aryliminophosphoranes

“…The reaction appeared to be a quite general, easy and useful method for the synthesis of 1,2-disubstituted benzimidazoles, as a final step of the synthetic route from simple nitroarenes through N-aryl-2-nitrosoanilines 1,2 and the corresponding iminophosphoranes. The yields are high and independent of the substituents present in both aromatic rings, and of the acid chloride used.…”

“…1,2 The reaction, which proceeded via reductive substitution of aromatic hydrogen, did not require the presence of a nucleofuge group and allowed for the synthesis of a number of 2-arylamino-substituted nitrosoarenes. The latter, bearing two differently polarized groups, proved to be valuable starting materials in the synthesis of various nitrogen heterocycles.…”

“…This arrangement creates a system in which both nitrogen atoms, and to some extent also the N-aryl ring, become disposed to reactions with electrophilic reagents. From our previous work it became clear that reactions of 1 with alkyl isocyanates, CS 2 and CO 2 proceed via initial addition of the iminophosphorane nitrogen atom to the carbonyl group of the other reagent, while the reactions with nitrous acid, leading to the benzotriazole system, seems to proceed in two different ways, including one involving initial nitrosation of the arylamine nitrogen atom. 10 In this paper we present the results of reactions of 2-(arylamino)aryliminophosphoranes (1) with simple acylating agents such as acid chlorides and Vilsmeier reagents.…”