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Organolithium and organosodium compounds of 1,2-dimethyl-, 1-methyl-2-ethyl-, 1-methyl-2-propyl-, and 1-phenyl-2-methylbenzimidazole, containing the metal in the alkyl group at position C(2), were obtained by metallation. It was found that metallation can be complicated by the addition of the metalling reagent at the C=N bond of the heterocycle. It was shown that the obtained organometallic compounds can be used for the synthesis of various derivatives of benzimidazole.

1.The electrophysical properties of several aromatic betaines without conjugation between the charged atoms have been examined.2.The dielectric constants of the substances studied turn out to be somewhat higher than those of most organic compounds and lie in the range 2.9–3.9.3.The temperature dependence of the electric conductivity of the betaines tested is described by an exponential law holding for most organic substances.4.Changes in the molecules causing easier excitability of the electron systems normally lowers the “activation energy” of the electric conductivity.

The hydrochlorides of the corresponding 2-benzimidazolylmethylhydroxamoyl chlorides were synthesized by the chlorination of 1-methyl-2-formylbenzimidazole oxime and its 5-methyl and 5-nitro derivatives, and 2-benzimidazolylmethylnitrolic acids were obtained by nitration of the oximes. The products of these transformations react with acetylacetone and benzoylacetone in the presence of bases to give 1',5'-substituted 3-[2-benzimidazolyl]-4-acyl-5-methylisoxazoles.

The reaction of 2-aminomethyl- and 2-aminomethyl-1-methylbenzimidazoles with nitrous acid was investigated. The reaction proceeds with nitrogen evolution with excess hydrochloric or hydrobromic acids to form 2-chloro- and 2-bromomethylbenzimidazoles, while 2-benzimidazolylmethylnitrolic acids and other products are obtained with excess nitrous acid.

The fine structure of some N-substituted 2-imino-1,3-dimethyl-benzimidazolines is examined with the aid of IR spectroscopy. It is shown that the introduction of an alkyl or phenyl group into the imino group does not affect the C=N group or the imidazoline ring structure. In salts of 2-imino-1,3-dimethylbenzimidazoline and its N-substituted derivatives, the heterocyclic system has the benzimidazolium structure. The structure of 2-imino-1,3-dimethylbenzimidazolines in which the exocyclic nitrogen atom has electrophilic substituents which are conjugated with the heterocycle is characterized by a considerable contribution from dipolar forms, with the imidazole ring bearing a positive charge.

It was shown by IR spectroscopy that 2-benzazolonitrile oxides, which are formed by the action of triethylamine on 2-benzazolylmethylhydroxamoyl chlorides, are extremely labile; the presence and nature of a substituent near the fulmide group and the basicity of the heterocyclic fragment of the molecule have a great effect on their stabilities.

A number of N-aminomerhyl and N-alkoxy(aroxy)methylbenzimidazoles are prepared. These compounds are decomposed in acid solution, giving benzimidazole. Sodamide reacts with them to give N-aminomethylbenzimidazole, and not the corresponding 2-amino derivative. The facility with which the compounds investigated decompose decreases in the order N-aminomethyl > N-aroxymethyl > N-alkoxymethylbenzimidazole. The mechanism of splitting is considered.

Reaction of the 2‐alkylbenzimidazoles (I) with the lithium or sodium compounds (II) gives the α‐metallated derivatives (III).