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☛ Official ☚ The Big & Dandy βK-2C-B Thread - Part 1

King Kong

Aug 19, 2006
Welcome to the βK-2C-B (bk-2C-B) Thread


Wikipedia: Bk-2C-B


Marquis reagent test result

[original post:]

In these times of ketones, I wondered if anyone had tried bk-2cb?
I think is correct name is 2-amino-1-(4-Bromo-2,5-dimethoxyphenyl)ethan-1-one, right? I cann't find any informations on this molecule!
I think it can be very psychoactive. Moreover, as the 2c-b is illegal, Rc's vendors could used bk-2cb as an alternative "legal"! But I don't see things like this... What is the reason?

And, if someone have informations...

Thanks for you answers!
Hope I don't say stupids things... And sorry for my poor english!
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Na-uhhh, it forms a dimer with itself because the amine is unprotected - it reacts with the ketone on another molecule of it's own type.
Sorry. (otherwise yeah it'd probably be active)

(This is why bk-MDMA can exist, because it's a secondary amine, but bk-MDA can't, because it's a primary amine.)
(And no, you can't just methylate the amine to get around this because the N-methyl derivs of PEA psychedelics are either very low potency or inactive. Pity, really...)
dimerisation is favored under alkaline conditions. cathinone seems to be stable in living catha edulis but is rapidly reduced to cathine and norephedrine after the plant is harvested.
What does it dimerise to that can't be hydrolysed back? Am i being stupid?

BOB does sound good tho.
I believe izo is right.
Yeah ok so it CAN exist the problem is that the synthesis and isolation is difficult because as soon as you get a >7 pH you start to form the dimer because the amine is no longer protonated as a salt, so in this case you would get 2,5-bis(4-bromo-2,5-dimethoxyphenyl)pyrazine I think. I'm not entirely sure of the dimerisation mechanism, I think the ketone groups leave, and you get the aromatic pyrazine ring formed as a results which is a NON-REVERSIBLE reaction.
So yes it can be made but it's difficult to keep stable, you'd end up with a soup of hard to seperate product, which only gets worse every time you try and purify it (because you'd want to A/B it to do so, which just forms more dimer...)
If you could seperate it cleanly and quckly, and form the HCl salt, and then keep it in a tightly sealed container, it would be okay. Whether this is too much hassle is up to you.


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I guess it forms the bis-imine dimer which oxidises to give the stable aromatic ring. Could make it from an acid labile n-protected precursor then i guess.

Curious to see if fastandbulbous' suggestion of a beta methylene works.
If it forms the imine-dimer isn't that reversible? It just happens to form a more stable product because of the symmetry/ring formation. I'm not sure exactly how the conjugated ring would form. This is the product I am seeing, and I think it would be reversible.

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Yeah formation of the imine dimer is reversible, however loss of two protons (not sure of the mechanism, maybe start with a kinda enolate fromation) gives a stable aromatic compound, so eventually given the right (or wrong) conditions it will be the only product
The place to look is Khat. Khat produces a beta-keto phenethylamine (cathinone). How does it exist? Do other alkaloids or compounds keep it from dimerisation?

If cathinone can exist, so can the beta-keto-2Cs. Plus, I've read Shulgin spoke of trying them at the 2006 Basil conference and confirmed they were active.
Maybe 'cause it's not in an aqueous environment. I also suspect the dimer is in an equilibrium with the non-cyclic form.
For sure, in Khat, cathinone is present as it's free base, not as a salt. So there is something keeping it from dimerising.
(As for the reversibility of it, yeah imine formation should normally be reversible but the aromatic system formed here should be quite stable so it's formation is favored - this is what makes me think there will be an equilibrium involved)
Yeah it will be in equilibrium up till imine formation, formation of the aromatic ring tho is formally an oxidation (hydride has to be lost) so is irreversible except in the presence of strong reducing agents. For the imine, more water would, i would think shift equilibrium to the ketone
Indeed, though i'm not a chemistry-g33k. It does seem very complex to get there or maybe impossible..

Thanks for bringing an old and interesting thread back to life. :)

but cathinone is instable, and I always thought this was because it is a primary amine? and as far as I know, it decomposes to cathine and norephedrine, not some dimer?

what if one would attach a hydroxy group to the nitrous? according to shulign, N-OH phenethylamines are pretty much equivalent in action to their counterparts without the OH group. would the hydroxylation protect beta-keton-phenethylamines from being instabile?
OH groups readily fall off from phenethylamines. See the PiHKAL entry on FLEA. There's a reason it hasn't been out as an RC. (It'd be pretty much identical to MDMA...)
The Small & Handy βK-2C-B (bk-2C-B) Thread

I was lucky enough to try this compound some months ago. I was impressed even though my efforts were as usual an investigation into the threshold effects. These came on at the 50 - 60mg area but it's said that 100mg or more is needed for a proper trip. My doses were small, through the day but the effects were very similar to that which I have enjoyed on low doses of other similar duration 2c-xx's.

I havent found any molecule pics yet but I'll edit this when I do!
[mod edit: pic added but moved to OP]
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Interesting. Added structural formula and edited TT to make it the same as others, but I removed the chemical formula name from the TT because it was incorrect (missing the amine part, the NH2 visible on the right, which is definitely a part of 2C-B). Until I can someone to confirm that my suggestion "(1-(4-bromo-2,5-dimethoxyphenyl))-2-aminoethan-1-one" is IUPAC correct or generally okay let's leave it out of the TT. Maybe the amino comes first, since that is alphabetical.

Let's hope it grows into a B&D indeed because that might imply some form of success, and who doesn't like a decent chem? If it is so weak though, it had better be worth it - otherwise it would not be economical and merely retains novelty value.
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