I can only point out that while most people seem to think that the nitazenes are a new drug are unaware that the first recorded clandestine laboratory in Spain in 1966 and it appears the chemists quickly realized it was just far too toxic but it was discovered in and around the south east of the nation. Then the more famous example in Germany in 1987 during a severed 'heroin drought) and, once again, it was quickly abandoned.
Only then do we read of the case in Russia in which a brilliant but disabled organic chemist who could not find work syntheized a batch and for the first time (as far as I can work out) stuck with the toxicity problem. In the end it was dissolved in a low MW alcohol and using a long needle and syringe, a single cigarette could be produced that did not contain a fatal dose. It was still considered quite unpleasent BUT as with some other unusual opioids, did have a small group who had a preference for the stuff.
The fact that it appeared to be nothing more than a cheap unfiltered Russian cigarette meant that a bit like DMT, fans who had to wait 30 minutes for a bus or train could smoke a laced cigarette, get off there tits for 20 minutes and come down enough to continue their day. BUT finding that dose killed quite a few 'guinea pigs'. But smoking and alcohol abuse were and are so prevelent in Russia, if a user 'monged out', they usually wouldn't die and alcohol would be assumed. By all accounts it simply wasn't very profitable if only because a user needed to redose so often. There weren't enough users with enough money to go through a pack or two of the laced fags every day.
Only in 2003 was the infamous Morton-Thiakol case in which one Dr. Thomas K. Highsmith made a batch, broke 'rule 1', discovered his life was spiralling out of control and knowing no high-level distributors, asked the janitor! Sad story because he had enough money to get bail and to get onto a private methadone programme BUT etonitazene is that worst thing of all, it's a SUPERagonist i.e. there is no dose of methadone compatible with life that would ameliorate what I can only presume is a truly horrific AWS. So he took his own life.
I don't think it's a secret that all of the above was only possible because of this 1975 paper made the class a facile target
https://sci-hub.st/10.1021/jm00237a024
Similarly, carfentanil laboratories seem to be turning up semi-regularly in Canada and my guess is that in the internet era, a decent organic chemist can produce carfentanil because a cheaper route to alfentanil was needed and just happened to generalize to related compounds.
https://sci-hub.st/10.1021/acschemneuro.5b00137
I'm sure we all know the story of who, where and why α-methyl fentanyl and 3-methyl fentanyl turned up when it did or that because fentanyl is still a widely used opioid, there are dozens of patents each one optimized to bring down the price as much as possible. I'm sure if people look, they will quickly find the three-step 92% overall yielding optimization of fentanyl synthesis. How it uses an acid halide in place of a closely watched acid anhydride and (if memory serves) the use of an unusual selective reductive amination step where STAB in DCM N-alkylates the uncontrolled aldehyde without reducing the ketone.
But my point is that none of these highly-potent opioids originated in China. It's just that IN China, production of an explicitly controlled opioid carries the death penalty so dezocine, dihydroetorphine, pethidine, methadone and even tramadol and buprenorphine have all been redirected by organized criminal gangs. Such is the opiophobia within China (also still very common in India where the British grew opium a century ago) that users keep an extremely low profile. The US experience of mitragynine appears to mirror that of China with strict legal controls only being enacted in 2024.
I just think the fentanyl synthesis has been so telescoped that semi-skilled 'cooks' can make it from loophole precursors imported from China because they have the lowest prices and ask the fewest questions. If a precursor is controlled, within a week they will be offering a pre-precursor. No explaination of utility, it's up to the buyer to figure out how to make use of it. It's now accepted BECAUSE of it's low price. Just last week a BBC film crew interviewed a user who had just bought a $4 'bag' which they proceeded to vape. It's the fact that such people need to redose so frequently is why it's so profitable. That's why I mentioned etonitazene. The two seem to have a lot in common in terms of it taking several attempts and crucially, the right legal and political changes to push people into using it.
I have a hypothesis that the 'cociniro' still use the same three key precursors but that in Mexico, because those precursors are uncontrolled, there is a kind of Gongkai (公开) culture where tricks are shared on the pragmatic basis that ultimately, money is always the goal and the grey-market precursor manufacturers accept that knowledge is fluid and while yes, there certainly are examples of Chinese suppliers essentially selling 'kits' including synthetic protocols, the person who can produce at the lowest price will win (at least in the short term).
I can only presume the ONLY reason that 4-phenylphenapromide (4PP) and related haven't turned up yet is because fentanyl is still cheaper. Assuming that the raecemate is the target, it would 'only' be x30M and the most potent of the series (I'm CERTAIN of) is 4-phenyl-4-hydroxylphenapromide (4POP) would 'only' be x75M.
I do apolgise for the long read but I do help out some HR agencies whenever they need a nerd. I would be watching for 4PP turning up as a metric to see IF US measures to stop fentanyl production are working. AFAIK the two are more or less identical in every way so I wouldn't expect users to note the change.
There is a LOT of other novel scaffolds so to me it seems insane to so focus on fentanyl that IF someone made the conscious decision to produce a 'premium' product at a much higher price, it's quite likely it would take law enforcement a year to identify and of course by that point, the next 'premium' product replaces it.
I'm slightly annoyed that someone with 1 post will open up on how amazeballz some incredibly obscure opioid IS when at most all we have is it's analgesic activity in animal models. Since the 1960s there have been various stratergies to develop a less-abusable opioid but if a ligand turns up in one or two articles and 50+ years later someone just ASSUMES the qualitative activity and safety mirror such small studies, people will get hurt.
I absolutely agree with
@Dextro .45 pointing out that medically, out of tens of thousands of potential opioid analgesic, only a few dozen are in use. It isn't a co-incidence that with only a few exceptions potency is less that x20 morphine. Something estimated to be x30000 morphine will be by definition an insummountable agonist i.e. even if a patient (or victim in cases of unprescribed use) is treated using the most potent antagonists available, it won't help. Something Janssen found (and abandoned) in the 1960s are now turning up and who knows why Janssen abandoned them?