An overview of radio or stable isotope‐labeled cis‐neonicotinoid analogs

Abstract

To support the metabolism and toxicology study of cis‐neonicotinoids, radio or stable isotope was introduced into different sites of the key intermediate 2‐chloro‐5‐((2‐(nitromethylene)imidazolidin‐1‐yl)methyl)pyridine (6‐Cl‐PMNI). [3H2]‐ and [14C]‐label were successively prepared from initial materials NaB3H4 and [14C]‐nitromethane, respectively. Similarly, [D2]‐6‐Cl‐PMNI was prepared from NaBD4 in four steps, with 52.6% overall isotopic yield, and dual‐labeled [D2, 13C]‐target was obtained from NaBD4 and [13C]‐nitromethane, affording overall isotopic yield of 42.5%. Moreover, [14C2] was introduced from [U‐14C]‐ethylenediamine dihydrochloride in three steps, with a 58.3% overall chemical yield. Finally, typical labeled cis‐neonicotinoids paichongding and cycloxaprid were prepared and characterized. The methods were proved to have good generality in the synthesis of other cis‐neonicotinoids, and all results would be useful in metabolism studies of new cis‐neonicotinoids. Copyright © 2012 John Wiley & Sons, Ltd.

18F‐Labeling of Sensitive Biomolecules for Positron Emission Tomography

“…reported the synthesis of a novel fluorine-18 labeled aromatic alkyne, 4- [18 F]fluoro-3-nitro- N -2-prop-1-ynylbenzamide ( [18 F]FNPB, 105 ) as a stable prosthetic group for efficient click labeling of peptides. [100] [18 F]FNPB was synthesized in 58% overall yield and in vitro studies showed no radiodefluorination in mouse plasma over 2h, suggesting stability in vivo as well. A novel approach was described by using an alkyne functionalized fluorine-18 labeled trifluoroborate building block 106 as the coupling partner to azido containing biomolecules such as bombesin and RGD peptide (Figure 18B).…”

Nicotinische Acetylcholinrezeptor‐Agonisten: ein Meilenstein für den modernen Pflanzenschutz

“…Die Zwischenstufe IPP-10 (rac-37) hat sowohl Kontakt-als auch systemische Wirkung und zeigt Pflanzensystemizität mit letalen und subletalen Auswirkungen auf die Haferblattlaus (Rhopalosiphum padi l.) auf Weizen. [83] rac-38 (Gemisch aus vier Diastereomeren, zwei Enantiomerenpaare) [84] [85] Für rac-38 konnte von seinem 2-Chlor-1,3thiazol-5-ylmethyl-Bioisoster vor kurzem eine hohe insektizide Wirkung gegen Bohnenblattläuse (A. craccivora) nachgewiesen werden. [86]…”