Preparation method for 8-benzyl-3-(3-isopropyl-5-methyl-4H-1,2,4-triazole-4-base)-8-azabicyclo[3.2.1]octane

The invention discloses a preparation method for 8-benzyl-3-(3-isopropyl-5-methyl-4H-1,2,4-triazole-4-base)-8-azabicyclo[3.2.1]octane. The preparation method comprises the following steps of: heating and refluxing N-(8-benzyl-8-azabicyclo[3.2.1]octyl-3-base)isobutyramide serving as a raw material and a vulcanization reagent in a non-proton solvent to obtain N-(8-benzyl-8-aza-bicyclo[3.2.1]octyl-3-base)isobutyl sulfamide; making sodium alcoholate react with halogenated hydrocarbon or sulfate to obtain N-(8-benzyl-8-aza-bicyclo[3.2.1]octyl-3-base)isobutyl imine acid thioester; heating and refluxing an alcohol with 2-5 carbon atoms and acethydrazide to obtain crude 8-benzyl-3-(3-isopropyl-5-methyl-4H-1,2,4-triazole-4-base)-8-aza-bicyclo[3.2.1]octane; and refining normal heptane and ethyl acetate to obtain a high-purify target product. Due to the adoption of the method for preparing the 8-benzyl-3-(3-isopropyl-5-methyl-4H-1,2,4-triazole-4-base)-8-azabicyclo[3.2.1]octane, water is prevented from interfering an intermediate reaction process, the yield is high, and the product purity is high.