PROCESS FOR PREPARATION OF BORONIC ACID INTERMEDIATES Russian patent published in 2018 - IPC C07F5/02 

FIELD: chemistry.

SUBSTANCE: present invention relates to a process for the preparation of a compound of formula (I) . Method includes steps of a) adding a compound of formula (II) , where each R¹ and R² is independently C_1-6 alkyl, to a solution of the compound of formula (III) , and an immobilised acid catalyst in a polar aprotic organic solvent with a boiling point above 100°C, wherein Hal is F, Cl, Br or I, to produce a compound of formula (IV) , and b) reacting a mixture of a compound of formula (IV) and a compound of formula (V) with a metalation reagent (V), where each R³, R⁴ and R⁵ is independently C_1-6 alkyl, in a polar aprotic organic solvent at a temperature of -90°C to -95°C, and c) hydrolysing the compound obtained in step b) to obtain a compound of formula (I).

EFFECT: invention makes it possible to prepare a boronic acid compound (I) with high purity and high yield.

19 cl, 4 ex