Synthesis of ring- and side-chain-substituted m-iodobenzylguanidine analogues.
With the goal of developing MIBG analogues with improved targeting properties especially for oncologic applications, several radioiodinated ring- and side-chain-substituted MIBG analogues were synthesized. Except for 3-[(131)I]iodo-4-nitrobenzylguanidine and N-hydroxy-3-[(131)I]iodobenzylguanidine, the radioiodinated analogues were prepared at no-carrier-added levels from their respective tin precursors. The radiochemical yields generally were in the range of 70-90% except for 3-amino-5-[(131)I]iodobenzylguanidine for which a radiochemical yield of about 40% was obtained. While the silicon precursor N(1),N(2)-bis(tert-butyloxycarbonyl)-N(1)-(4-nitro-3-trimethylsilylbenzyl)guanidine did not yield 3-[(131)I]iodo-4-nitrobenzylguanidine, its deprotected derivative, N(1)-(4-nitro-3-trimethylsilylbenzyl)guanidine was radioiodinated in a modest yield of 20% providing 3-[(131)I]iodo-4-nitrobenzylguanidine. Exchange radioiodination of 3-iodo-4-nitrobenzylguanidine gave 3-[(131)I]iodo-4-nitrobenzylguanidine in 80% radiochemical yield. No-carrier-added [(131)I]NHIBG was prepared from its silicon precursor N(1)-hydroxy-N(3)-(3-trimethylsilylbenzyl)guanidine in 85% radiochemical yield.
Vaidyanathan
G
G
Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA. ganesan.v@duke.edu
Shankar
S
S
Zalutsky
M R
MR
D019797:3-Iodobenzylguanidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D000970:Antineoplastic Agents / Q000138:chemical synthesis; D002713:Chlorine; D020650:Combinatorial Chemistry Techniques; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D055672:Static Electricity
D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D002713:Chlorine