Diastereomer of Fosaprepitant dimeglumine

Diastereomer of Fosaprepitant dimeglumine is a stereoisomeric impurity retaining the fundamental morpholin-4-yl, 1,2,4-triazol-4-yl, and 3,5-bis(trifluoromethyl)phenyl structural framework of Fosaprepitant. Its chemical constitution maintains the C3-substituted 3,5-bis(trifluoromethyl)phenyl group and the C4-substituted 2-(morpholin-4-yl)ethyl dihydrogen phosphate moiety linked to the triazole ring. However, it exhibits an inverted absolute configuration at one or more (but not all) of the chiral centers present in the parent drug's non-phosphate portion, distinct from the predominant (R,R,R) stereochemistry. This compound is instrumental as an HPLC reference standard for chromatographic resolution and quantification of stereoisomeric impurities in Fosaprepitant drug substance.