Novel method for preparing important intermediate of minodronate

Abstract

The invention relates to a method for preparing 2-(imidazo[1,2-a]pyridine-2-pyridinyl) acetic acid of a compound in a formula (I). In the method, trans-4-oxo-2-crotonate and 2-aminopyridine in a compound of a formula (II) perform a condensation reaction, and are hydrolyzed to form the compound of the formula (I). The compound is an important intermediate for preparing the minodronate.

Description

technical field The invention relates to a preparation method of 2-(imidazo[1,2-a]pyridin-3-yl)acetic acid, which can be used as an intermediate for preparing minodronic acid. Background technique Minodronic acid, the chemical name is 1-hydroxy-2-[(imidazo[1,2-a]pyridin-3-yl)]ethylene-1,1-bisphosphonic acid, developed by Japan Yamanouchi Company The novel heterocyclic bisphosphonic acid compound is used for the treatment of osteoporosis. The results of pharmacological experiments show that the activity of this product in inhibiting bone resorption is disodium incadronate (disodium incadronate), alendronate sodium (alendronate) and 2, 10 and 100 times that of disodium pamidronate. Its chemical structure is as follows: minodronic acid Compound shown in formula (I) is the important intermediate of synthetic minodronic acid, and the synthetic method of minodronic acid is reported in EP0354806 respectively, and its preparation technology is: The preparation process route d...

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Problems solved by technology

Wherein 4-ethyl bromoacetoacetate is difficult to buy, and its synthetic method will use a large amount of bromine to carry out the bromination reaction to make this route industrialization comparatively difficult

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