The application provides a preparation method of
bumetanide, and relates to the technical field of biological
medicine synthesis. 4-chloro-3-nitro-5-sulfonamidobenzoic acid, an alkaline
reagent,
phenol and water are mixed to perform a phenoxylation reaction, the obtained 3-nitro-4-phenoxy-5-sulfonamidobenzoic acid is mixed with a
reducing agent and
palladium carbon to perform a reduction reaction, the obtained 3-amino-4-phenoxy-5-sulfonamidobenzoic acid is mixed with n-butyl
aldehyde,
sodium triacetoxyborohydride and an
organic solvent to perform a
reductive amination reaction, and then
bumetanide is obtained. The preparation method provided by the application has a high total yield of products. Moreover, the preparation method provided by the application has the advantages of wide
raw material sources, simple synthesis process
route, mild
reaction conditions, few by-products, high product quality, low cost and suitability for industrial production. As shown in the test results of examples, the total yield of
bumetanide prepared by the preparation method provided by the application is more than 37.5%.