Sumatriptan-Inter, 5 cynoindole

Sumatriptan-Inter, 5-cyanoindole is a structurally related impurity derived from the indole core of sumatriptan, featuring a cyano substituent at the C5 position of the indole ring. This compound lacks the sulfonamide and propyl side chains of the parent drug, retaining only the aromatic indole framework with a nitrile functional group. It arises as a synthetic intermediate during sumatriptan production via cyano group introduction prior to side-chain attachment. The compound serves as a critical HPLC reference standard for quantifying process-related impurities in sumatriptan active pharmaceutical ingredients.