Preparation method of small-granularity atomoxetine hydrochloride crystal

The invention relates to a preparation method of small-granularity atomoxetine hydrochloride crystals. The HPLC (High Performance Liquid Chromatography) purity of the high-purity atomoxetine hydrochloride can reach 99.85% or above, and the small granularity means that the main granularity D50 is 10-20 microns. The preparation method comprises the following steps: slowly dropwise adding acyl chloride into an alcohol solvent under the condition of stirring at room temperature, carrying out heat preservation and stirring after dropwise adding, then dropwise adding an ether solvent of an atomoxetine crude product into a system, filtering, washing a filter cake by using the alcohol solvent, and drying to obtain a high-purity small-granularity atomoxetine hydrochloride crystal product. According to the method, the atomoxetine hydrochloride bulk drug with high purity and controllable particle size distribution can be obtained without crushing, and the method is high in yield, simple and easy to implement, low in cos