Imidazole-4,5-dicarbaldehyde

The reaction of imidazole-4,5-dicarbaldehyde with 2-aminoethylpyridine in the presence of copper(II) chloride has enabled the preparation of a binuclear complex (equation 2).29 A more common class of binuclear complex is based on template reactions of a phenolic dialdehyde with various amines and includes the copper complexes (14)30 31 and (15).32 Reactions of this type can be extended to the synthesis of macrocyclic binuclear complexes such as (16).33,34... 

Acyl-substituted imidazoles have distinctive UV and IR spectra, and can exist as hydrates in solution, e.g. imidazole-2-carbaldehyde. The aldehyde group is sufficiently electron withdrawing to assist nucleophilic displacement of an adjacent halogen atom. The normal aldehyde derivatives such as oximes, acetals and hydrazones can be formed, and the kinetics of oxime formation with the 4-carbaldehyde have been studied. The tautomeric ratio (zwitterion uncharged aldehyde form) of 1-substituted imidazole- and benzimidazole-2-aldoximes rises in parallel with an increase in basicity of the parent molecule (73CHE1074). These compounds have been shown by NMR studies to adopt the syn configuration. With hydrazine hydrate, imidazole-4,5-dicarbaldehydes give imidazo[4,5-d]pyridazines (208 Scheme 110). 

Scheme 11 Oxidation of imidazoie diol to give imidazole-4,5-dicarbaldehyde. ...

A bimetallic Pt/Bi/C catalyst was used for the oxidation of imidazole diol to give imidazole-4,5-dicarbaldehyde, a key step in the synthesis of pro-drugs of hepatitis C virus replicase inhibitors (Scheme 11). ... 

Bowman RK, Brown AD, Cobb JH. Synthesis of HCV rephcase inhibitors base-catalyzed synthesb of protected a-hydrazino esters and selective aerobic oxidation with catalytic Pt/Bi/C for synthesis of imidazole-4,5-dicarbaldehyde. J Org Chem. 2013 78 11680-11690. 

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