Tritium labelling and characterization of the potent imidazoline I1 receptor antagonist [5,7-3H] (±)-efaroxan at high specific activity

(±)-Efaroxan 1 is a selective antagonist at the imidazoline I1 receptor. [3H] (±)-Efaroxan was required to explore its mechanism of action via receptor binding assay, and the radioligand was prepared by means of catalytic dehalogenation of a dibrominated precursor with tritium.