Kirdanova T.S., Zadorozhnii P.V., Kiselev V.V., Kharchenko A.V.
SHEE “Ukrainian State University of Chemical Technology”,
New feasible routes for the preparation of the novel 1,3-benzimidazole derivatives are described. These heterocycles have been directly obtained in one-pot reaction by refluxing of equivalent amounts of amines, N-(2,2,2-trichloro-1-isothiocyanatoethyl)carboxamides in acetonitrile, then adding dicyclohexylcarbodiimide with the 25 % exess of dicyclohexylcarbodiimide (DCC) as a cyclodesulfurizing agent. A detailed study of the interaction of previously obtained benzimidazoles with an excess of primary and secondary amines has shown that in all cases the conversion is accompanied by dehydrochlorination and substitution of the amide moiety to the aminogroup and with formation of the corresponding the N-benzimidazo-2,2-dichloroacetamidines.
Compound 5 has been prepared in acceptable yields and without special difficulties isolated from the reaction mixture.
The structures of the synthesized compounds have been fully characterized by IR, 1H NMR, 13C NMR, mass spectrometric data and elemental analysis.