Linagliptin Related compound C

Linagliptin Related Compound C is a structurally analogous impurity derived from the parent drug, characterized by a substituted naphthalene core linked to a tetrahydrofuran-pyrrolidine scaffold via an amino methylene bridge. It retains the 1,1-dioxido-3-isopropyl-1H-benzotriazole moiety but lacks the terminal sulfonamide group present in linagliptin, resulting in a truncated naphthalene-2-yl substituent. This compound arises as a synthetic precursor during the final sulfonation step, forming a key process-related impurity. It serves as an HPLC reference standard for quantifying this specific impurity in linagliptin active pharmaceutical ingredients.