The invention discloses a type of 2-(2,3-dimethyl phenyl) diester
malonate, a preparation method thereof, and an application thereof in an intermediate 1-(2,3-dimethyl phenyl)
ethanol used for synthesizing
dexmedetomidine hydrochloride. According to the invention, 2,3-dimethylbenzoic acid is adopted as an initial
raw material. The initial
raw material is chlorized into 2,3-dimethylbenzoyl
chloride. 2,3-dimethylbenzoyl
chloride is subject to a reaction with diester
malonate under the existences of
triethanolamine and
magnesium chloride anhydrous, such that 2-(2,3-dimethyl phenyl) diester
malonate is obtained. 2-(2,3-dimethyl phenyl) diester malonate is hydrolyzed with
sulfuric acid, such that 1-(2,3-dimethyl phenyl)ethanone is obtained. 1-(2,3-dimethyl phenyl)ethanone is then reduced by a
reducing agent, such that 1-(2,3-dimethyl phenyl)
ethanol is obtained. The operation of the method is simple and convenient; the raw materials of the method are cheap and are easy to obtain; the
reaction conditions are mild; and the purity of the finished products is high. With the method provided by the invention, special separating and purifying are not required. The method is suitable to be applied in large-scale productions.