Method for preparing minodronic acid intermediate

The invention relates to the field of medicine synthesis, in particular to a method for preparing a minodronic acid intermediate 2-(imidazo[1,2-a]pyridin-3-yl)acetic acid (I). The method is characterized by comprising the following steps of: performing condensation on 3-bromoimidazo[1,2-a]pyridine (II) and diethyl malonate to obtain 2-(imidazo[1,2-a]pyridin-3-yl)diethyl malonate (III); and hydrolyzing and performing decarboxylation to obtain the 2-(imidazo[1,2-a]pyridin-3-yl)acetic acid (I). The method has the advantages of cheap and readily available raw materials, a few reaction steps, simple operation, high product quality, low cost, suitability for industrial production and the like.