3-Pyrrolidineacetamide, 1-[2-(2,3-dihydro-5-benzofuranyl)ethyl]-α,α-diphenyl-, 1-oxide

Darifenacin N-oxide is a potential impurity found in commercial preparations of the muscarinic acetylcholine receptor (mAChR) antagonist darifenacin.¹ It is a degradation product formed under oxidative conditions.

1. Thomas, S., Paul, S.K., Shandilya, S., et al. Identification and structural elucidation of two process impurities and stress degradants in darifenacin hydrobromide active pharmaceutical ingredient by LC-ESI/MSn Analyst 137(15),3571-3582(2012).