Novel preparation of (R, R)bromo-3-quinuclidinylbenzilate (Br-QNB), a precursor for the synthesis of (R, R)[123I]iodo-QNB

Abstract

NOTENovel preparation of (R,R)Bromo-3-Quinuclidinylbenzilate (Br-QNB), a precursor for the synthesis of (R,R) a-hydro~-a-(4-bromophenyl)-a-phenylacetate) described previously was modified. Radiolabelling with iodine-123 was achieved using a copper(1) assisted nucleophilic exchange reaction resulting in high specific activity (80 GBq/pmol) and an overall yield of 56 %. azabicyclo[2.2.2]oct-3-yl-(R)-(+)-

Radiohalogen incorporation into organic systems

“…The product showed high specific activity (80 TBq mmol À1 ). 150 Another preparation of IQNB, labelled with either [I-123] or [I-127], was described earlier. 151 Analogously, iodine-labelled epibatidine, 70, was prepared from the bromopyridyl compound through iodode-bromination, using [I-123]-or [I-125]-NaI at high temperatures ) and a Cu(I) catalyst.…”