Synthesis of 123I‐and labelled 5‐iodo‐6‐nitroquipazine

The syntheses of the potent and selective serotonin reuptake complex radioligands [123I]‐ and [125I]5‐iodo‐6‐nitroquipazine (5‐iodo‐6‐nitro‐2‐piperazinylquinoline) are reported. A seven step synthetic sequence provided the BOC‐protected 5‐tributyltin‐6‐nitroquipazine precursor for radioiodination. End of synthesis radioiodination yields of ∼40% for 123I and ∼60% for 125I were achieved resulting in labelled products with high specific activities (>4000 and >2000 Ci/mmol, respectively) and radiochemical purities (>98%).