The utilization of green chemistry techniques is dramatically reducing chemicalwaste and reaction times as has recently been proven in several organic syntheses and chemicaltransformations. To illustrate these advantages in the synthesis of bioactive heterocycles, we have studied various environmentally benign protocols that involve greener alternatives. Herein we are reporting a greener and general methodology for the synthesis of a small library of 2-nitroimidazoles including azomycin and its differently substituted analogs. The present protocol involves the reaction of 2-aminoimdazoles with NaNO2 in dry condition, catalysed by a natural clay, which is preanalyzed to be an iron rich kaolinite clay, under microwave condition. Use of solid acid clay catalyst instead of strong mineral acids under solvent-free condition along with simple work up is a major significance of this method.