Radiosynthesis of [tetrazoyl-11C]irbesartan, a non-peptidic angiotensin II antagonist

Article abstract of DOI:10.1016/S0223-5234(97)88917-9

With the aim of visualizing myocardial angiotensin II receptors (AT1 subtypes), [tetrazoyl-¹¹C]2-n-butyl-1-[(2'-(1H-tetrazol-5-yl)-1,1'-biphenyl-4-yl)methyl] - 4-spirocyclo-pentane-2-imidazoline-5-one ([tetrazoyl-¹¹C]irbesartan (SR47436/BMS-186295)) 11 was synthesized in one pot in four steps from [¹¹C]hydrogen cyanide. The labelling process which yielded [tetrazoyl-¹¹C]irbesartan is described in detail and could be applied to the labelling of other ligands which possess the (1H-tetrazol-5-yl) moiety. Positron emission tomography (PET) studies were performed in dogs. Heart, lung and blood time-activity curves did not change. Therefore this new radioligand is not suitable for studying myocardial angiotensin II receptors with PET.