| Abstract: | The previously unknown 2-(pyrazol-4-yl)benzimidazoles containing aryl groups in the pyrazolyl ring have been obtained by the reaction of 2-phenacyl-1H-benzimidazole with aroylhydrazines. The compounds with nitrophenyl and pyridyl substituents in the pyrazole ring show pyrazolyl tautomerism with differences in the1H NMR spectra. A semi-empirical method is proposed to determine the tautomeric composition of the synthesized pyrazoles.Institute of Organic Chemistry, Ukraine National Academy of Sciences, Kiev 253660; e-mail: iochkiev@sovam.com. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1512–1518, November, 1999. |
