This invention belongs to the field of
organic synthesis technology and provides a method for preparing a key intermediate of
ambroxol hydrochloride. The method includes the following steps: methyl 2-aminobenzoate reacts with a brominating
reagent under the action of an initiator to generate methyl 2-amino-3,5-dibromobenzoate via a bromination reaction; subsequently, methyl 2-amino-3,5-dibromobenzoate is reduced to 2-amino-3,5-dibromobenzyl
alcohol in a reduction
system; finally, under the action of an
oxidizing agent, 2-amino-3,5-dibromobenzyl
alcohol is further oxidized to form the target compound 2-amino-3,5-dibromobenzaldehyde. The optimized process has mild
reaction conditions, conforms to green and
environmentally friendly principles, significantly improves
route safety, uses inexpensive and readily available raw materials, and achieves high product yield and purity, making it suitable for industrial production.