The invention discloses a preparation method of
scopolamine butylbromide, comprising the steps of: (1) subjecting
scopolamine and n-
butyl bromide to heating under
reflux to complete reaction; (2) preparing a crude product of
scopolamine butylbromide; and (3) refining the crude product of scopolamine butylbromide. By means of the invention, by utilizing the physicochemical property that n-
butyl bromide has excellent dissolubility for scopolamine, but poor dissolubility for
reaction product scopolamine butylbromide, the scopolamine and excessive n-
butyl bromide are reacted, and thus the yield of scopolamine butylbromide is improved by raising
reaction temperature, increasing
reaction speed and shortening reaction time. In the preparation method of scopolamine butylbromide, disclosed by the invention, the use of any medium is avoided, the n-butyl
bromide is not only used as a
raw material for synthesizing scopolamine butylbromide, but also as a reaction
solvent with stable properties, excessive n-butyl
bromide can be recovered and treated relatively easily after the reaction is finished and can be repeatedly used, and thus, cost reduction is facilitated, and environment is protected.