Preparation method of memantinehydrochloride

The invention discloses a preparation method of memantinehydrochloride, which comprises the steps of enabling 1-bromine-3,5-dimethyl adamantane and acetamide to have amination reaction at the reaction temperature of 50-180 DEG C and with the response time for 0.25-10 hours, directly adding alcohol and inorganic aqueous alkali after completion of the amination reaction at the temperature of 100-200 DEG C for 1-30 hours, obtaining extraction matters through organic solvent extraction, enabling the extraction matters to be reacted with muriatic acid to obtain coarse products of the memantinehydrochloride, and obtaining target products of the memantinehydrochloride through recrystallization of the coarse products of the memantinehydrochloride by using recrystallization solvent finally. The preparation method avoids using toxic chemical reagents, simplifies operating steps, improves yield coefficient, and lowers production cost.