131179-95-8Relevant articles and documents
Trimethylaluminium mediated amide bond formation in a continuous flow microreactor as key to the synthesis of rimonabant and efaproxiral
Gustafsson, Tomas,Ponten, Fritiof,Seeberger, Peter H.
, p. 1100 - 1102 (2008/09/21)
A safe, functional-group-tolerant and high-throughput version of the trimethylaluminium mediated amide bond formation reaction has been developed in a microreactor system; rimonabant and efaproxiral were prepared to illustrate the utility of the method. The Royal Society of Chemistry.
Mass spectrometric characterization of efaproxiral (RSR13) and its implementation into doping controls using liquid chromatography-atmospheric pressure ionization-tandem mass spectrometry
Thevis, Mario,Krug, Oliver,Schaenzer, Wilhelm
, p. 332 - 338 (2007/10/03)
Efaproxiral (2-[4-[[(3,5-dimethylanilino)carbonyl]methyl]phenoxyl]-2- methylpropionic acid, formerly referred to as RSR13) is prohibited in sports according to the World Anti-Doping Agency (WADA). The drug as well as structurally related compounds and a stable isotope-labeled derivative have been synthesized to elucidate the fragmentation pathway of efaproxiral, using electrospray ionization (ESI) and tandem mass spectrometry by employing a novel linear ion trap - orbitrap hybrid mass spectrometer - in positive and negative ionization modes. The elimination of 2-methyl acrylic acid (-86 u) has been identified as a major fragmentation process in both charge states. Negative ionization and collision-induced dissociation (CID) caused an additional release of carbon dioxide (-44 u), and positive ionization the loss of formic acid (-46 u). Efaproxiral was incorporated into an existing screening procedure for doping controls using solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry, enabling a limit of detection of 2.5 ng/ml and interday precisions ranging from 7.9 to 13.0%. Copyright