Preparative access to transformation products (TPs) of furosemide: a versatile application of anodic oxidation

Furosemide, a pharmaceutical prescribed for the treatment of edema and hypertension, is a known contaminant of water. In this study, chemoselective anodic oxidation was implemented to assist in the identification and the preparation of furosemide transformation products (TPs), i.e., compounds deriving from furosemide and likely to appear in the environment. An aniline and a pyridinium are proposed as plausible TPs and an analytical study of the pyridinium is presented.