IMPROVED METHOD OF PRODUCING 4-BENZIMIDAZOLYL METHYLAMINO)-BENZAMIDE SALTS Russian patent published in 2011 - IPC C07D235/14 

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing optionally substituted 4-benzimidazol-2-ylmethylamino)-benzamidine of formula (I) with organic or inorganic acids , in which R¹, R² and R³ are as described in claim 1, characterised by that (a) phenyldiamine of formula

in which R¹ and R² assume values indicated for formula (I), are condensed with 2-[4-(1,2,4-oxadiazol-5-on-3-yl)-phenylamino]-acetic acid and (b) i) the obtained product of formula in which R¹ and R² assume values given for formula (I) is hydrogenated, ii) the amidine group is optionally carbonylated without pre-extraction of the hydrogenation intermediate product and iii) the obtained compound of formula (I), in which R³ denotes hydrogen, without pre-extraction of the carbonylation intermediate product, optionally react with a compound of formula (IV) R³-X (IV) in which R³ assumes values given for formula (I), and X denotes a suitable splitting group, and the desired salt is separated.

EFFECT: novel method enables to obtain the desired compound with high output and using cheap auxiliary material.

10 cl, 7 ex