4-Imidazolecarboxylic acid (1H-imidazole-4-carboxylic acid, H₂imc) is an imidazole derivative that contains an imidazole group and a carboxylate group. It has been widely utilized to generate different types of coordination polymers. The anion of 4-imidazolecarboxylic acid has been reported to stabilize binuclear hydroxo complexes of trivalent lanthanides in the pH range 7-10.

4-Imidazolecarboxylic acid (ICA) was used in the synthesis of triphenymethyl-protected 4-imidazole carboxylic acid (trityl-ImCOOH) which is employed to functionalize poly(propylene imine) dendrimers.
It may be used in the following studies:

• In the synthesis of lanthanide sulfate–carboxylates, [Ln(HIMC)(SO₄)(H₂O)] (Ln = Dy and Eu, HIMC = 4-imidazolecarboxylic acid) by in situ decarboxylation in the presence of Cu(II) ions.
• As an internal standard to obtain calibration curve by plotting the peak area ratios of histamine (HA) and several metabolites isolated from C3H/HeNCrj mice hair relative to ICA.
• In the synthesis of tetranuclear manganese carboxylate complexes possessing imidazole-based N/O chelating ligands.

For a review of imidazoles, see Science of Synthesis.