Ivacaftor carboxylate

Ivacaftor carboxylate is a structurally related impurity derived from the parent drug Ivacaftor, characterized by the incorporation of a carboxylate ester moiety at the terminal cyclopropane-substituted tetrahydrofuran ring. This compound retains the core pyridine-fused chromen-4-one scaffold but features an additional oxygenated ester functionality, altering its hydrophobicity and ionization profile. The presence of a 1-azabicyclo[2.2.2]octane ring system and a meta-substituted benzene ring further defines its pharmacophoric framework. It arises as a specific synthetic byproduct during API manufacturing, serving as a critical HPLC reference standard for quantitative impurity profiling in Ivacaftor formulations.