NOVELTY - Preparing (P1) imipramine (I) or its hydrochloride salt, comprises: e.g. (a) condensing iminodibenzyl with N,N-dimethylaminopropyl chloride in presence of alkali metal hydroxide and N,N-dimethylacetamide in an inert organic solvent at a temperature of 90-95 degrees C; (b) removing insolubles and washing the resultant solution with water to obtain an organic layer; (c) extracting obtained organic layer with aqueous hydrochloric acid; (d) separating aqueous acidic layer and basifying aqueous acidic layer to a pH of 9-12 with aqueous alkali metal hydroxide; and (e) extracting obtained basified solution.    USE - The process is useful for preparing imipramine or its hydrochloride salt (claimed), which is useful for treating major depression and enuresis. No biological data given.    ADVANTAGE - The process: provides (I) with GC purity of more than 98.5%, and imipramine hydrochloride having HPLC purity of more than 99.5% (claimed), and high yield; is simple, economic, eco-friendly, reproducible and robust, as compared to conventional processes; and reduces the formation of byproducts.    DETAILED DESCRIPTION - Preparing (P1) imipramine of formula (I) or its hydrochloride salt, comprises: (a) condensing iminodibenzyl with N,N-dimethylaminopropyl chloride in presence of alkali metal hydroxide and N,N-dimethylacetamide in an inert organic solvent at a temperature of 90-95 degrees C; (b) removing insolubles and washing the resultant solution with water to obtain an organic layer; (c) extracting the obtained organic layer with an aqueous hydrochloric acid; (d) separating an aqueous acidic layer and basifying the aqueous acidic layer to a pH of 9-12 with an aqueous alkali metal hydroxide; (e) extracting the obtained basified solution with an organic solvent comprising an aliphatic hydrocarbon; (f) separating a hydrocarbon layer, charcoalizing and evaporating to obtain imipramine base (I) with gas chromatography (GC) purity of more than 98.5%; and (g) optionally dissolving (I) in acetone, cooling to 5-10 degrees C, adjusting pH to 3-5 with an alcoholic hydrochloride and isolating imipramine hydrochloride having HPLC purity of more than 99.5%. An INDEPENDENT CLAIM is also included for preparing (P2) imipramine hydrochloride, comprising the steps (a)-(f) as above per se, and dissolving (I) in acetone, cooling to 5-10 degrees C, adjusting pH to 3-5 with an alcoholic hydrochloride and isolating imipramine hydrochloride having HPLC purity of more than 99.5%.