Alumina-promoted synthesis of N-aryl-1,2,4-triazoles from substituted hydrazines and imides

Herein we report the highly efficient, environmentally friendly alumina-promoted synthesis of N-aryl-1,2,4-triazoles with a wide variety of substitution patterns from commercially available hydrazines with symmetrical and unsymmetrical imides. Aromatic hydrazines with a variety of substitution patterns provided the corresponding 1,2,4-triazoles in very high yields. Unsymmetrical imides with a wide variety of functional groups also provide the respective triazoles with high yield and complete regioselectivities. The high productivity and mild conditions allow for the large-scale preparation of 1,2,4-triazoles.