Continuous flow synthesis process of anti-neocrown drug Ensitrevir intermediate

The invention discloses a continuous flow synthesis process of an anti-neocoronal drug Ensitrevir intermediate, and belongs to the technical field of medical intermediates. The method comprises the following steps: by taking 2-fluoro-4-chlorobenzaldehyde as a raw material, carrying out continuous flow nitration reaction on the 2-fluoro-4-chlorobenzaldehyde and concentrated sulfuric acid/concentrated nitric acid to obtain 2-fluoro-4-chloro-5-nitrobenzaldehyde, then carrying out ring closing reaction on the 2-fluoro-4-chloro-5-nitrobenzaldehyde and Boc-methylhydrazine to obtain 6-chloro-2-methyl-5-nitro-1-hydrogen-indazole, and finally carrying out reduction reaction in a dynamic screw reactor to obtain 6-chloro-2-methyl-5-nitro-1-hydrogen-indazole. And the intermediate 6-chloro-2-methyl-2H-indazole-5-amine, which is an anti-new crown drug Ensitrevir, is obtained. According to the continuous flow synthesis method, potential safety hazards of traditional nitration reaction are avoided, high selectivity is achiev