Study of halogenation of 5(6)-hydroxybenzimidazole and its derivatives

1. New halogen derivatives of 1-ethyl-2-methyl-, 2-methyl- and 5-hydroxybenzimidazole were obtained. 2. A method for the chlorination of aromatic compounds by an alcoholic solution of hydrogen chloride in the presence of hydrogen peroxide was proposed, which enables carrying out the reaction with a high yield. 3. The reactivity of the series of 5(6)-hydroxybenzimidazole derivatives during the electrophilic substitution (halogenation) was shown to be as follows: 1-ethyl-2-methyl-5-hydroxybenzimidazole >5(6)-hydroxybenzimidazole ≥ 2-methyl-5-hydroxybenzimidazole.