Synthesis of 14C-labelled 6-hydroxy-5,7-dimethyl-2-(methylamino)-4-(3-pyridylmethyl)benzothiazole dihydrochloride (14C-E3040 dihydrochloride)

14C‐Labelled 6‐hydroxy‐5,7‐dimethyl‐2‐(methylamino)‐4‐(3‐pyridylmethyl)‐benzothiazole dihydrochloride (14C‐E3040 dihydrochloride), required for a study of the phrmacokinetic profile of E3040, a novel dual inhibitor of 5‐lipoxygenase and thromboxane A2 synthetase, was synthesized in one step using [2‐14C]‐1‐methyl‐2‐thiourea as the labelled starting material. 14C‐E3040 dihydrochloride with a specific activity of 58.0mCi/mmol was prepared in 60% chemical yield(based on thiourea 2).