Doultegravir Imp F(Tri cyclic impurity)

Dolutegravir Impurity F is a tri-cyclic compound arising from an aberrant cyclization event during the synthesis of Dolutegravir, featuring a fused pyrimidine-benzene-lactam core with an esterified carboxylic acid side chain. Its structure incorporates a 1,2,4-triazole ring linked to a substituted pyrimidine, distinguishing it from the parent drug's pyridone moiety. The compound exhibits a rigid, planar conformation due to conjugated aromatic systems and an amidic linkage. This impurity is a critical synthetic byproduct formed via intramolecular nucleophilic attack during lactam formation. It serves as an HPLC reference standard for quantifying process-related impurities in Dolutegravir APIs.