Acylation of Tautomerizable C‐Amino‐Azoles with Amidine or Guanidine StructureAmino‐azoles can react with electrophiles to give different regioisomers. Stable ringacylated isomers were isolated at low temperatures and under neutral conditions. Acyl migrations are obtained at higher temperatures and under basic conditions to form the thermodynamic stable isomers.The different isomers can be characterized by mean of1H‐NMR,13C‐NMR, IR and mass spectrometry.The results obtained enable us to correct some confusions in the literature about the regioselectivity of the acylation of ami