The synthesis of [ 14 C]AZD5122. Incorporation of an IV 14 C‐microtracer dose into a first in human study to determine the absolute oral bioavailability of AZD5122

AZD5122, N ‐(2‐(2,3‐difluorobenzylthio)‐6‐((2 R ,3 R )‐3,4‐dihydroxybutan‐2‐ylamino)pyrimidin‐4‐yl)azetidine‐1‐sulfonamide was under investigation as a potential chemokine receptor CXCR2 antagonist for the treatment for inflammatory diseases. To gain a better understanding of the human pharmacokinetic profile, an exploratory phase I IV microtracer study was conducted using carbon‐14 radiolabelled AZD5122. [ 14 C]AZD5122 was carbon‐14 labelled in the pyrimidine ring in five steps in an overall radiochemical yield of 19% from [ 14 C]thiourea. The absolute oral bioavailability of AZD5122 was assessed in healthy subjects by an oral administration of AZD5122, followed by a concomitant intravenous [ 14 C]AZD5122 microdose.