The Present invention relates to simplified method for the production of fasciolicide and its derivative thereof. The derivative of fasciolicide can be produced by nitration and iodination of base compound in controlled manner. The present method is specifically related to production of 4-hydroxy-3-nitrobenzonitrile and its derivatives. In present method, controlled nitration of base compound is carried out by maintaining reactor temperature at optimum conditions. Present invention is also related to operating reactor for nitration reaction at optimized parameters which will provide selective nitration of base compound which will result in to lower operating cost of reactor and higher selective yield.
