An effective and scalable 14C radiolabelling of several biogenic indole derivatives at high specific activity

An efficient method is described to radiolabel several biogenic indole derivatives with carbon-14 at high specific activity. •This paper describes the carbon-14 labelling of several biogenic indoles including tryptamine and serotonin.•A common and efficient synthetic route is described to prepare these compounds which is both robust and scalable.•The synthetic products are analytically characterized at high radiopurity and specific activity.