(5S)-N,5-bis(4-fluorophenyl)-5- hydroxypentanamide

(5S)-N,5-bis(4-fluorophenyl)-5-hydroxypentanamide is a chiral amide derivative featuring a (5S)-configured hydroxypentyl chain substituted with two 4-fluorophenyl groups at the N-terminus and the 5-position. The molecule incorporates an amide linkage between the terminal nitrogen and the pentyl backbone, with a stereocenter at the hydroxylated carbon. This compound arises as a stereospecific synthetic byproduct during Ezetimibe production, differing from the parent drug by the presence of an additional hydroxyl group at the 5-position of the side chain. It serves as an HPLC reference standard for chiral impurity profiling in Ezetimibe active pharmaceutical ingredient (API) batches.