Vilazidone 5-cyano indole impurity

Vilazidone 5-cyano indole impurity is a structurally related synthetic byproduct characterized by a 5-cyano-substituted indole core, differing from the parent drug by the absence of the dibenzofuran moiety and presence of a cyano group at the indole C5 position. This impurity arises from a side reaction during Vilazidone synthesis, where cyano group introduction competes with the formation of the parent compound's piperazine-linked dibenzofuran scaffold. The molecule exhibits a planar indole framework with electron-withdrawing cyano functionality, contributing to distinct HPLC retention and NMR spectral features. It serves as a reference standard for quantifying process-specific impurities in Vilazidone active pharmaceutical ingredient (API) batches.