I was able to use this standard and it can’t to be use for quantitative analysis. It is not stable at room temperature and the standard turns back to the API form very quickly, in solution and/or in solid state.
We, as laboratory, were able to give a report with our findings regarding the no stability of the standard at different temperatures, from a standard that was in fact Nitroso-Ticagrelor. Additionally a justification report from another supplier justifying that the standard could not be synthesized from different methods was used to complete our justification report. I think this was enough with our client.
Hi yes I am just dissapointed that Nitroso-Ticagrelor remains so long in the EMA App1 even its stability/synthesisability issues compromises any possibility of quantitative testing…
Hi, what you observed is most likely the product of a 3+2 cycloaddition involving NO and the cyclopropyl ring. I attempted to prepare nitroso-ticagrelor using several different approaches, but the only product I was able to isolate was the corresponding oxazole derivative. This outcome is described in more detail here: