NOVELTY - Preparing anastrozole, comprises: (A1) a bromination step, in which 2,2'-(5-methyl-1,3-phenylene)bis(2-methylpropanenitrile) is subjected to bromination step in presence of an ester solvent to obtain 2-(3-bromoethyl-5-(cyano-dimethyl-methyl)-phenyl)-2-methyl-propanenitrile; (B1) a nucleophilic substitution step, in which organic mixture comprising e.g. unreacted 2,2'-(5-methyl-1,3-phenylene)bis(2-methylpropanenitrile) is caused to react in dimethylformamide with 1-2-4-triazole or its sodium salt at 0-25 degrees C for formation of anastrozole; and (C1) anastrozole purification step.    USE - The method is useful for preparing anastrozole (claimed), which is useful for treating advanced or recurrent breast cancer in post-menopausal women. No biological data given.    ADVANTAGE - The method: does not require the use of purification by column chromatography and recrystallization step, hence it is simple and cost effective; eliminates the steps of isolation and purification of the bromo derivative intermediate or other intermediates, hence it is environmentally friendly; and provides the anastrozole with improved purity and yield.    DETAILED DESCRIPTION - Preparing anastrozole, comprises: (A1) a bromination step, in which 2,2'-(5-methyl-1,3-phenylene)bis(2-methylpropanenitrile) is subjected to a bromination step in the presence of an ester solvent to obtain 2-(3-bromoethyl-5-(cyano-dimethyl-methyl)-phenyl)-2-methyl-propanenitrile; (B1) a nucleophilic substitution step, in which an organic mixture comprising unreacted 2,2'-(5-methyl-1,3-phenylene)bis(2-methylpropanenitrile), formed 2-(3-bromoethyl-5-(cyano-dimethyl-methyl)-phenyl)-2-methyl-propanenitrile and (if necessary) other reaction by-products is caused to react in dimethylformamide with 1-2-4-triazole or its sodium salt at a temperature of 0-25 degrees C for the formation of anastrozole; and (C1) an anastrozole purification step comprising (a) adding a mixture of an organic solvent immiscible with water and water to the solution resulting from the nucleophilic substitution step, (b) separating the organic phase from the water phase, (c) treating the organic phase with a water solution with a pH of 0.8-1.2 and subsequently separating, (d) treating the organic phase is with a water solution with a pH of not less than 0 and subsequently collecting the water phase, and (e) subjecting the acid water phase of the step (d) to a crystallization operation by means of a gradual pH variation through the addition of an alkaline solution, at a temperature of 0-15 degrees C, until a final PH value 5-7 is reached.