Highly Selective Synthesis of 2-(2H-1,2,3-Triazol-2-yl)benzoic Acids

A selective and scalable synthesis of 2-(2H-1,2,3-triazol-2-yl)benzoic acid starting from 1-fluoro-2-nitrobenzene derivatives is presented. The four-step synthesis introduces the triazole at the start via N2-arylation of 4,5-dibromo-2H-1,2,3-triazole. A sequence of consecutive functional group transformations, namely hydrogenation, Sandmeyer iodination, and Grignard carboxylation, provides the target molecules in a reliable and scalable manner. The usefulness of this method is demonstrated by the synthesis of di- or tri(2H-1,2,3-triazol-2-yl)benzene derivatives, which are difficult to produce by other methods.