In a continuation of the review [1] on methods for the synthesis of haloimidazoles it seemed of scientific and practical interest to examine and summarize also published data for 1965-2009 on the chemical and physicochemical properties and biological activity of this important group of heterocyclic compounds. PHYSICOCHEMICAL PROPERTIESHalo-and dihaloimidazoles are liquid, oily, or solid substances of basic character and form salts with mineral acids and picrates. The nitrates and picrates, which crystallize readily from water and lower alcohols, are quite often used for the additional characterization of compounds being studied.The basicity constants of 4,5-dicyano-2-haloimidazoles show that the 2-iodo derivative has higher basicity than the bromo-, chloro-, and fluoro-substituted analogs [2] (Table 1).According to data in [3] the 2-fluoro-and 4(5)-fluoroimidazoles are weaker bases than the corresponding bromoimidazoles (Table 2). 2,4,5-Trihaloimidazoles are solids lacking basic characteristics. 2,4,5-Tribromoimidazole (1) exhibits the properties of an acid and forms with dimethylamine the salt 2 with a yield of 64% [4]. N H N Br Br Br N N Br Br Br Me 2 NH 2 -+ 1 2 Me 2 NH Me 2 CO

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