C-H Amination of Nitro Azaheterocyclic Compounds by Vicarious Nucleophilic Substitution

Various nitro azaheterocyclic compounds were subjected to C-H amination by vicarious nucleophilic substitution with 4H-1,2,4-triazol-4-amine (ATA). The aminated products were characterized by NMR, mass spectroscopy, and single-crystal X-ray diffraction analyses. The substrates examined gave moderate to excellent yields (30-88%) and showed good regioselectivities. This protocol offers the advantages of mild conditions, a short reaction time (2-4 hours), and an inexpensive, commercially available, and less-toxic amination reagent; moreover, no additional catalyst or reagent is needed. A possible reaction mechanism is discussed.