Polyhalogenobenzimidazoles: synthesis and their inhibitory activity against casein kinases

Abstract

A series of novel polyhalogenated benzimidazoles have been prepared by exhaustive bromination of a variety of 2-substituted benzimidazoles. The efficacy of both new compounds and a number of their previously described cognates as inhibitors of casein kinases CK1, CK2 and G-CK was investigated. The type of N-1 alkyl substituent as well as introduction of a polyfluoroalkyl moiety at position 2 did not markedly influence the inhibitory efficacy toward CK2 of the respective 4,5,6,7-tetrabromobenzimidazole derivatives which conversely were almost ineffective toward CK1 and G-CK. However, 4,5,6,7-tetrabromobenzimidazoles substituted at position 2 with either chlorine, bromine or sulfur atom, while manifesting a still considerable inhibitory activity against CK2 (IC(50) in the 0.49-0.93 microM range) proved to be potentially powerful inhibitors also against CK1 (IC(50) in the 18.4-2.2 microM range).