METHOD OF SYNTHESIS OF BENZIMIDAZOLE DERIVATIVES OR THEIR SALTS Russian patent published in 1994 - IPC

FIELD: organic chemistry. SUBSTANCE: product - derivatives of benzimidazole of the general formula 1 and 2 indicated in description where R₁ is not obligatory substituted alkyl group; R₂ and R₃ are independently each of other represent the group which is able to form anion, or the group which can be converted to the such group; ring A - benzene ring which does not obligatory contain other substituents apart from the group R₂; X - direct bond of phenylene group and phenyl group or linkage through the spatial group chain atoms of which does not exceed 2, or their salts. Reagent 1: compound of the general formula 2. Reaction conditions: intramolecular cyclodehydration following by conversion of product prepared to the compound of formula 1 by azidation, hydrolysis, reduction, halogenation, nucleophilic reaction, cyaniding and/or esterification or compound of the formula 1 is converted to its salt. Synthesized compounds are used as pharmaceutical preparations. EFFECT: improved method of synthesis. 1 tbl