Linagliptin Des Piperidine amine

Linagliptin Des Piperidine amine is a structurally related impurity derived from the parent drug linagliptin, characterized by the absence of the piperidine ring and a desubstitution at the amine linkage. Its core structure comprises a sulfonamide-linked 5-(2-(3-pyridyl)ethyl)-1,2,3-thiadiazole moiety appended to a naphthalene-1-sulfonamide scaffold. The compound retains the thiadiazole and aromatic sulfonamide functional groups critical to linagliptin’s mechanism but lacks the piperidine-based side chain, resulting in altered pharmacokinetic properties. This impurity arises via synthetic pathway divergence during API synthesis, specifically during coupling reactions involving the amine functionality. It serves as an HPLC reference standard for impurity profiling in linagliptin drug substance analysis.