Dibenzimidazo crown ethers were synthesized by alkylation of α,ω-bis(benzimidazol-2-yl)alkanes and 1,2-bis(benzimidazol-2-ylsulfanyl)ethane with tri-and tetraethylene glycol bis(4-toluenesulfonates). The structure of 6,7,9,10,12,13,21,22-octahydro[1,14,6,9,4,11]dioxadithiadiazacyclohexadecino[4,5-a:11,10-a′]dibenzimidazole was studied by X-ray analysis.Demands in new multidentate ligands with specified properties determine persistent attention to the development of methods of preparation and studies on the structure of macroheterocycles with variable size of the ring and nature and number of donor centers, as well as of those possessing exocyclic coordination centers. In this connection, crown ethers containing a benzimidazole heteroring attract some interest. With a view to synthesize such macrocyclic compounds we used as starting materials a series of α,ω-bis(benzimidazol-2-yl)alkanes and 1,2-bis(benzimidazol-2-ylsulfanyl)ethane; their analogs are known as efficient ligands for coordination to copper(II) ions [1].The corresponding 15-, 16-, and 18-membered dibenzimidazo crown ethers Ia-Ic having two or three oxygen atoms in the macroring were synthesized by alkylation of bis(benzimidazol-2-yl)alkanes IIa and IIb with tri-and tetraethylene glycol bis(4-toluenesulfonates) in dimethylformamide (DMF) in the presence of potassium hydroxide under argon (Scheme 1). The yields of compounds Ia-Ic were 44-67%. Initial 1,2-bis(1H-benzimidazol-2-ylsulfanyl)ethane (IV) was prepared by alkylation of 2,3-dihydro-1H-benzimidazole-2-thione (III) with 1,2-dichloroethane in aqueous sodium hydroxide (Scheme 2). O TsO O OTs O O m m + n = 1, m = 1 (а); n = 1, m = 2 (b); n = 2, m = 1 (c). Scheme 1.