Pyrovalerone (upper image) was a stimulant developed in the 1960s. Pyrophenidone was discovered by accident while researching diphenidine. The idiot chemists placed a pyrrolidine in place of the piperidine specified. The result turned out to be a very smooth stimulant (cocaine snorters loved it - it's action is almost identical to prolintane). Activity noted, the team tried adding a ketone to explore QSAR and it turned out to be more potent. Finally a p-Me was added which increased activity and reduced duration.
It would appear that the right-hand benzene ring can in fact be many different 5 & 6 membered aromatics. If memory serves a 2-furyl replaces the benzene in one analogue.
It's also worth noting that for the aryl-n-pentane class of stimulants, replacing the terminal -CH3 with a -CH2F seems to work. The products are a bit less soluble and in certain cases, the phosphate addition salt is preferred. In fact, the reason nitrocaine sucked was because it's lack of solubility meant that it couldn't be snorted... the phosphate, on the other hand....
BTW the team also tried this - it wasn't as good. A 3,4-methylenedioxy WILL likely work but a p-Me is simpler and better. I'm sure people will see how this work relates to the 1,2-diarylethylamine class of NMDA antagonists such as diphenidine. Amazingly,1 of the diphenidine analogues is as good as K but it slipped through the floorboards....
But the cool thing is, it can be made in 1 step using cheap precursors. I took it with my wife and when we touched finger to finger, we couldn't work out where one person ended and the other began (K++).
If I had to pick one, I would pick:
The former is certainly active (and smooth) while the latter avoids the legal problems associated with an 'alkyl chain of 2-6 carbons' since it's a fluoroalkyl. Again, go for phosphate as hydrochlorides tend to have poor solubility and hurt whensnorted.
Now I remember the name - Zylofluramine.
Now it's a second ring BUT it isn't aromatic which suggests that a LOT of things can replace the second phenyl in pyrophenidone.
US2921076
US3091621
It looks like people designing new RCs can make hundreds from the above patents.
