METHOD OF PRODUCING 2,2-BISBENZIDAZOLE Russian patent published in 2011 - IPC C07D235/20 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing nitrogen-containing heterocyclic rings, specifically to 2,2'-bisbenzimidazole, which involves reaction of methyl ether of 3-(4-chlorophenyl)-3-chloro-2-oxo propanoic acid and 1,2-diaminobenzene in acetic acid at room temperature in molar ratio 1:1 for 12 hours and extracting the 3-(α-chloro-4-chlorobenzyl)-2-oxo-1,2-dihydroquinoxaline precipitate; and then reaction of 3-(α-chloro-4-chlorobenzyl)-2-oxo-1,2-dihydroquinoxaline and 1,2-diaminobenzene in molar ratio 1:1 in dimethylsulphoxide at room temperature for not less than five days, dilution with water, leaching with aqueous solution of NaHCO₃ until precipitation, extraction of the precipitate, boiling the solution of this precipitate in acetic acid for 2 hours and extracting the desired compound through filtration.

EFFECT: novel method of producing 2,2'-bisbenzimidazole, which is characterised by simplicity and efficiency, as well as use of readily available starting compounds.

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