AbstractThe synthesis of tripodal carboxamide ligands using one‐pot phosphite coupling reactions with nitrilotriacetic acid (NTA) and 4‐substituted anilines is well established. Generation of such tripodal ligands using ortho‐substituted anilines (2,6−RArNH2, R=F, Me, iPr) has proven to be challenging. The reaction between NTA and 2,6−RArNH2 using triphenylphosphite as a coupling reagent did not yield the desired tripodal carboxamide. Rather, the formation of 3,5‐dioxo‐1‐piperazine intramolecular coupling products N‐(2,6‐difluorophenyl)‐3,5‐dioxo‐1‐piperazine‐N‐(2,6‐difluorophenyl)acetamide (1), N‐(2,6‐dimethyphenyl)‐3,5‐dioxo‐1‐piperazine‐N‐(2,6‐dimethylphenyl)acetamide (2) and N‐(2,6‐diisopropylphenyl)‐3,5‐dioxo‐1‐piperazine‐N‐(2,6‐diisopropylphenyl)acetamide (3) was observed. All three compounds have been extensively characterized using nuclear magnetic resonance, Fourier‐transform infra‐red and mass spectrometry. X‐ray diffraction analysis yielded solid state structures of 2 and 3. Substituents at the ortho position of aniline thus favours intramolecular cyclization over the formation of tripodal carboxamide ligands, preventing preparation of the desired bulky ligand.