Continuous synthesis method of 3-chloro-5-(trifluoromethyl)-2-ethylaminopyridine hydrochloride

The invention discloses a continuous synthesis method of drug intermediate 3-chloro-5-(trifluoromethyl)-2-ethylaminopyridine hydrochloride. The continuous synthesis method comprises the following steps: taking ethyl cyanoacetate and 2, 3-dichloro-5-(trifluoromethyl) pyridine as raw materials, firstly reacting under the action of a catalyst and an alkali to obtain a reaction mother solution of intermediate 2-[3-chloro-5-(trifluoromethyl)-2-pyridyl] ethyl cyanoacetate, and then realizing direct hydrogenation reduction of the reaction mother solution under the action of the catalyst, and after removing the solvent, carrying out reflux reaction by using N, N-dimethylformamide with the pH value of 2-5 as the solvent to obtain the 3-chloro-5-(trifluoromethyl)-2-ethylaminopyridine hydrochloride.The synthesis method adopted by the invention reduces reaction steps, is simple to operate, less in three wastes and high in yield, and is the continuous synthesis method of the drug intermediate 3-chloro-5-(trifluoromethyl)-