(This is a verbatim copy of this post that originally made on reddit)
So for maximum clarity, in this post, FXE refers to 3F-2'-Oxo-PCE, CanKet refers to 2F-2'-Oxo-PCE. I am going to say "FXE" when I refer to the batches of drugs that have erroneously referred to as FXE.
The tl;dr is this:
Save for a single sample I tested this previous summer, 3F-2'-Oxo-PCE has not been widely sold online, and almost all of what we have been calling "FXE" for the last 2 years is actually 2F-2'-Oxo-PCE. But real FXE, 3F-2'Oxo-PCE does indeed exist- though in a very limited scope under the confusion of this nomenclatural confusion.
2F-2'-Oxo-PCE is what was identified in Australia and labeled as "CanKet"/2F-NENDCK/2F-NENK in reality, it was just regular old "FXE" that had entered their drug supply, the Canberra lab was just the first one to actually correctly identify it, as they used NMR, which is not used by most drug testing services. Without a standard, 3F-2'-Oxo-PCE and 2F-2'-Oxo-PCE will appear identical via GCMS, and all of us took the word of the lab that originally synthesized and continues to synthesize "FXE" and assumed the 3-Fluoro substituted compound was what was being tested.
What follows is an explanation of how I determined this and the evidence.
So I recently happened upon this post:
Which brought to my attention something I had missed on drugsdata.org- If you look at any of their tested samples of "FXE", they are now identified as "2F-2'-Oxo-PCE", which is also the drug that has been labeled as "CanKet" in Australia.
They all include this statement:
All samples analyzed by the DrugsData lab prior to early 2023 that were reported as containing Fluorexetamine have been reexamined in comparison to this new standard. They have all been retroactively revised; they all contain 2-Fluoro-2-oxo PCE, including this sample. To date, no samples tested by DrugsData have contained 3-Fluoro-2-oxo PCE.
This update was appended in late April 2023- no idea why it didn't make more waves then, I am sure some people caught on but clearly there is little awareness about this!
Anyways, I found this claim to be extraordinary, I had to find this out for myself. How could this happen? How could such a widespread drug have been mischaracterized for almost 2 entire years now?
The issue lies in analytical methods- the primary means of identifying drugs is GCMS, which gives you the distinct molecular weight of a compound. The only problem is, 3F-2'-Oxo-PCE and 2F-2'-Oxo-PCE are compositionally identical, and would have the same molecular weight. What IS distinctive is their retention time when running GCMS- this is the point in time when the compound is detected, and while this doesn't predictably quantifiably correspond to a specific property of each compound, it can at least help us differentiate between two compounds of identical mass. Unfortunately, this is only an effective means of differentiation if there is a known standard to compare it to. What likely happened is that almost all of the "FXE" in the world was coming from a single source, which was taken at its word that this was the compound being produced. Maybe this was a typo, or maybe they misidentified what they themselves were making. I am not going to speculate as to what caused this misunderstanding, it is not something that really happens by accident though, the reagents required to make one compound vs. the other are entirely different. But anyways, the samples from this source that was supposedly trustworthy were used as a standard, under the assumption that they were the 3-substituted FXE, creating a self-replicating chain of misinformation. This highlights the importance of using independently manufactured standards! Preferably from a reputable source like Cayman.
So without a standard on hand, how do you differentiate between these 2 compounds? Enter nuclear magnetic resonance, or NMR. Owing to the cost, NMR is not available to or used by most drug testing services, which is why this has escaped notice for so long. The Canberra testing service, CanTEST, was able to perform NMR testing at the University in which they are based, which is why they were the first to correctly identify this compound. I will not pretend to understand how it works, but I do know how to interpret the results to some degree. NMR is the best tool for determining the structure of an unknown molecule, not just its composition. The graph that is returned corresponds to interactions between the different components of the molecule, and from there the actual structure and placement of the different atoms can precisely be determined. To get an idea of how a 2-Fluoro substitution would appear, I ran a sample of 2F-DCK (confirmed via GCMS w/ retention time) as a reference.
The sample was obtained in May 2023, and originally came from a lab in China. The nmr was run as 1H NMR (400 MHz, DMSO-d6). I was returned 2 graphs. I have zoomed in on the area corresponding to the subtituted phenyl ring.
The placement of a substitution on a phenyl ring will give back different patterns of peaks. A 2-position substitution is distinguished by having 4 separate sets of peaks corresponding to the different unique hydrogens on the ring. These 4 peaks will then manifest as two sets of two distinct patterns: 2 doublets of doublets and 2 triplets of doublets (which will be further split apart by Fluorine in this example). We don't need to go into what that means, all that matters is, that same pattern is seen in this region of the graph for 2F-DCK and "FXE"- and this tells us that the "FXE" has a substitution on its 2 position, not its 3 position.
So that sealed it, I had a sample of a compound that was sold as FXE, but was confirmed to actually be CanKet, or 2F-2'-Oxo-PCE. I could now use this sample as a reference for other analytical methods that would be a lot faster and simpler, namely GCMS.
Now i have a quick reference for whether a sample is 2F-2'-Oxo-PCE!
This is what the GCMS for 2F-2'-Oxo-PCE looks like. So now we have a characteristic retention time (~12.79 min) and diagnostic mass peaks for the major fragments (~178.16 and 207.21). But perhaps this was just a sampling issue- maybe its only recent batches of "FXE" that have been misrepresented! Well I had also tested the very first batch of "FXE" to hit the market- the one that was contaminated with the stimulant A-D2PV. Lo and behold, the same retention time, the same mass (not visible in the picture I forgot to highlight the peak sorry). Almost all "FXE" has been coming from China, as did these two batches. I can say with confidence that any "FXE" being sold out of China, unless otherwise specified, is 2F-2'-Oxo-PCE.
So has real FXE ever existed? The answer is: Yes! I tested a sample for a friend back in July of this year- Curiously, this has the same major fragments as the mass (178, 207), but it has a different retention time: 13.39! I don't have this sample on hand anymore to confirm this via nmr, but if the mass is exactly the same, it can be presumed that this random sample was indeed a batch of genuine FXE that somebody out there had made separate from the current flow of "FXE". Interestingly enough the friend had reported this batch was much more potent than other batches of FXE and had very different effects. Ironically, I think at the time I concluded that this was an errant sample of CanKet!
FXE is too embedded into our collective conscience to correct the name to something like 2-FXE. Perhaps when batches of the genuine material appear, they must annoyingly be referred to as 3-FXE. That is for the community to decide. This is a stark and appalling example of misinformation spreading from taking a vendor at their word.
