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NEW METHOD FOR THE SYNTHESIS OF 2-SUBSTITUTED BENZIMIDAZOLE-5(6)-CARBOXYLIC ACIDS

Вахид Абдулла-оглы Мамедов, Елена Анатольевна Хафизова, Виктор Васильевич Сякаев, Ольга Борисовна Базанова, Анастасия Ильясовна Замалетдинова, Ильдар Хамидович Ризванов, Шамиль Камильевич Латыпов, Олег Герольдович Синяшин
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Abstract


A new method is proposed for the synthesis of 2-substituted benzimidazole-5(6)-carboxylic acids. The acid-catalyzed rearrangement of 2(3)-aroyl-3(2)-oxo-3,4(1,2)-dihydroquinoxaline-6-carboxylic acids was shown to proceed with the formation of 2-(3-arylquinoxalin-2yl)-1H-benzimidazole-5(6)-carboxylic acids. NMR studies of the rearrangement reaction product, 2-(3-phenylquinoxalin-2-yl)-1H-benzimidazole-6-carboxylic acid, indicated that it existed as a mixture of two tautomeric forms due to benzimidazole tautomerism under the NMR conditions. The carboxyl group of the synthesized benzimidazoles was used for the preparation of new derivatives.

 


Keywords


4-aminobenzoic acid derivatives, benzimidazole-5(6)-carboxylic acids, 2,5'-bibenzimidazoles, 2-oxo-3,4-dihydroquinoxaline-6-carboxylic acids, o-phenylenediamine, Mamedov rearrangement.

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