2-(Arylamino)aryliminophosphoranes, easily obtained from 2-nitrosodiarylamines,were found to be convenient starting materials for simple reactions with common acylating reagents such as acid chlorides and the Vilsmeier reagent. The reactions allow for the synthesis of 1,2-disubstituted benzimidazoles or dibenzo [b,e][1,4]diazepines, depending on the substituents on the 2-arylamine nitrogen atom.

Synthesis. -(LUKASIK, E.; WROBEL*, Z.; Synlett 25 (2014) 2, 217-220, http://dx.doi.org/10.1055/s-0033-1340055 ; Inst. Org. Chem., Pol. Acad. Sci., PL-01-224 Warsaw, Pol.; Eng.) -M. Tismer 28-195

1-Aryl-1,2,3-benzotriazole systems are synthesized in the high-yielding cyclocondensation of 2-(arylamino)aryliminophosphoranes under mild conditions. The reaction concludes the three-step, halogen-free synthetic route starting from simple nitroarenes and arylamines.

Deoxygenation of 2‐nitrodiarylamines by triphenylphosphine is presented as an efficient method for synthesis of 2‐(arylamino)aryliminophosphoranes, useful as starting materials in the synthesis of benzannulated nitrogen heterocycles. The reaction is complementary for the known synthesis of aryliminophosphoranes from 2‐nitrosodiarylamines giving rise to obtain the title products in the broader scope. The presented protocol is simple and efficient although limited to secondary 2‐nitrodiarylamines.