METHOD OF PRODUCING BENZIMIDAZOLES Russian patent published in 2013 - IPC C07D403/14 

FIELD: chemistry.

SUBSTANCE: invention relates to basic organic synthesis and specifically to a method of producing N,N'-bis and N,N,N,N-tetrakis-benzimidazolylmethyl N,N'-bis (piperazinoethyl) ethylenediamines, N,N'-bis and N,N,N,N-tetrakis-benzimidazolylethyl-N,N'-bis (piperazinoethyl) ethylenediamines, which are obtained by reacting carboxylic acids: N,N'-bis and N,N,N,N-tetrakis-carboxyethyl and N,N'-bis and N,N,N,N-tetrakis-carboxyethyl N,N'-bis (piperazinoethyl) ethylenediamine with ortho-phenylenediamine while heating first at temperature of 100-125°C for 0.6-1.5 hours and then at 130-150°C for 2.5-3.4 hours in the medium of an aromatic organic solvent with molar ratio hexamino diacid: phenylenediamine=1:2.1-2.15 and hexamino tetracid:phenylenediamine=1:4.1-4.15. The end product is separated by distilling the reaction mass. The aromatic organic solvent used is ortho-, meta- and para-xylenes or a mixture of ortho-, meta- and para-xylenes.

EFFECT: high output of end products, improved method of producing benzimidazoles.

2 cl, 1 tbl, 6 ex