2CB.HCl synthese

icecool · Insistent Chemist

Can it be done in a rotavappor?
And do you need to apply vacuum, or would that fuck up SWIM's vacuumpump?
SWIM has got an fumehood so that shouldn't bee a problem.

Radiumhero · Sun Aug 21, 2005 11:49 pm

it would take an enourmous amount of heat and alot of KBr/ NaBr to get the Br2 fumes up the kondensor , when swirh didnt have good labgrade Br2
he wanted to do it that way in his Büchi Rotavapor r but well the whole purpele reddish fumes stayed down in the rxn vessle so take a little 100ml roundbottom
flask( half filles with Nabr) and directly attache a kondensor to shorten the ways for the fumes best would perhaps be a liebig k .. but the choice is up to you ..

anime · Mon Aug 22, 2005 1:15 am

Its going to stain all your labware.
Enourmous amount of heat is unecessary if you first convert the KBr to Br2 via H2SO4/H2O2.

icecool · Insistent Chemist

Is it correct that the Br2 will float on top of the water, at least that's what it looks like when not adding DCM.
And what about extracting the Br2 with DCM, and then letting the DCM evaporate or put it on 30*C so it will evaporate quicker and then add (or do it before) adding acetic acid glacial...

Radiumhero · Mon Aug 22, 2005 4:38 pm

hmm no ur br2 should not be on top !
it should be below as a dark red liquid nothing on top since the molarweight and density of bromine are much higher than the mw of water...

icecool · Insistent Chemist

Hmm then it'll probably be DCM which some times keep floating on the top as little droplets.
If you touch them with a glass stir rod they will sink to the bottom.
Anyway again there didn't form an light brown paste with SWIM's 2C-B synthese.
He had 1,6ml of 2C-H and added DCM+Br2 to it.
Next time he'll use the Br2 pure not dissolved in DCM but he will extract it with DCM and then let the DCM evaporate...and then add GAA.
Anyway now it has been in the freezer for an hour or so and there are now light brown crystals or at least some solid, it more looks like "peel verse" but then a bit wet peel verse just found this word in the dictionairy dunno how to explain it it are more like very little sheets which are soft...
And well most of the people get >80% conversion from 2C-H to 2C-B.HBr so SWIM should have around > 1g of 2C-B.HBr mind that DCM is present in the mixture and in total there was used 2g KBr with the other chemicals in the right ratio added to it to form bromine which was extracted in DCM...
The 2C-H did heat up and formed crystals which quickly disapeared again after GAA was added it heated up to 40°C!!!
Then after the DCM+Br2 was added to that with stirring no heat was evolved it only rised 1°C.
From 26 to 27°C.
Anyway next time SWIM will use the method descriped before with DCM extraction -> evaporation --> GAA addition.
P.S Any idea's on what to do to get more crystals, let the DCM evaporate out of the total mixture?
Scratch the walls with a glas stirring rod?
Add MgSO4 as there might be some water in the mixture (2C-B.HBr is very soluable in water).
SWIM also heard using an addition funnel with on the bottom an cotton wad on top of that MgSO4 (anhydrous) and then on top of that another wad, then pouring the mixture threw it, it should dry it too without MgSO4 getting in the mix with 2C-B.HBr

icecool · Insistent Chemist

Hmm then it'll probably be DCM which some times keep floating on the top as little droplets.
If you touch them with a glass stir rod they will sink to the bottom.
Anyway again there didn't form an light brown paste with SWIM's 2C-B synthese.
He had 1,6ml of 2C-H and added DCM+Br2 to it.
Next time he'll use the Br2 pure not dissolved in DCM but he will extract it with DCM and then let the DCM evaporate...and then add GAA.
Anyway now it has been in the freezer for an hour or so and there are now light brown crystals or at least some solid, it more looks like "peel verse" but then a bit wet peel verse just found this word in the dictionairy dunno how to explain it it are more like very little sheets which are soft...
And well most of the people get >80% conversion from 2C-H to 2C-B.HBr so SWIM should have around > 1g of 2C-B.HBr mind that DCM is present in the mixture and in total there was used 2g KBr with the other chemicals in the right ratio added to it to form bromine which was extracted in DCM...
The 2C-H did heat up and formed crystals which quickly disapeared again after GAA was added it heated up to 40°C!!!
Then after the DCM+Br2 was added to that with stirring no heat was evolved it only rised 1°C.
From 26 to 27°C.
Anyway next time SWIM will use the method descriped before with DCM extraction -> evaporation --> GAA addition.

Radiumhero · Tue Aug 23, 2005 1:59 am

By tomorrow Swirh make some 2 , 5 dimethoxynitropropne ( i like it hard ^^ )
and reduce the hell outof it by some neat Al/ amalgam heard that this rxn doesnt really gives good yields and the diffrence between rxn yields will eat up the
advance of Dob´s strenth -.- well lets see ill prepare some styrene too ...

icecool · Insistent Chemist

Okay people, SWIM just got 10mg of very pure 2C-B.HBr after washing with GAA.
He saved the GAA washes and the liquid which contains bromine.
He only got 10mg out of 1,6ml freebase, so there just MUST be more in there.
Even if it wasn't pure freebase there still has to be more somewhere, SWIM let the DCM evaporate and now only Br2 and freebase is left in the liquid (should be Br2 and 2C-B.HBr now, anyway there did form some light brown crystals but not much that was when the DCM was still in there.
Next time SWIM will use pure Br2 for sure, anyway any idea's on how to get this lost 2C-B.HBr?
First SWIM will add GAA to the liquid and then put it in the freezer to see if there will be more crystals formed.
If not he will basify it and thus extracting the 2C-B freebase and then washing it with water to get rid of crap, then acidifying it and washing with DCM to get out other crap then make it alkaline again (ph >14) and extracting with DCM and then letting the DCM evaporate and then add a bit of water and then adding 29% HCl to it.
To get 2C-B.HCl from the rest that should be left...

Good idea?

EDIT: Now SWIM told me the beaker is one solid mass, as it should be, anyway SWIM guesses it is the acetic acid which froze now, but there might be loads of crystals inside which you cannot see now because of the brown frozen solid mass, since the crystals are brown too....
Anyway tomorrow SWIM'll throw the chunk of frozen stuff in the buchner filter and vacuum filtrate it to see what remains.

mrmacgoo4002 · Thu Sep 08, 2005 1:33 pm

Hi,

I've just been reading the 2c-b synth from rhodium at:

http://leda.lycaeum.org/Documents/2C-B_Synthesis.11171.shtml

and was curious as to what sort of yields are to be expected from the synth using the quantities outlined in the above link.

I am not particularly keen in attempting the synth, but am curious as to how many grams of 2c-b would be procurred from the initial 100g of 2,5-Dimethoxybenzaldehyde.

If anybody has any idea I would be interested in knowing what a standard yield from the procedure would be. I major in chem at uni, and read over such synths out of interest, most however state at the end what the yield was, however in this case it has not been noted.

Thanks.

icecool · Insistent Chemist

It is right in the synthese...it would yield 20g that way.
And doing Al/Hg would also I guess yield 20g or so, 2C-B gives shitty yields.
Al/Hg gives crap yields, at least at SWIM it always does like 20%.
Some people say they got 70% yield from Al/Hg dunno what substrate they used but well it depends on a lot of factors.

mrmacgoo4002 · Thu Sep 15, 2005 9:37 am

Was solid nitromethane used in this synthesis?

I had initially assumed a liquid had been used, however Phikal and Rhodium both refer to 200g of nitromethane, rather than 200ml.

Probably a stupid question, I know, however any information would be appreciated.

icecool · Insistent Chemist

Nitromethane is a liquid, and you can calculate on the hand of density how much ml 200g is...

Can 2C-H also be steam distilled and will it also form an azeotrope with water at 98-99°C?
Just like with amphetamine freebase it also comes over at 98-99°C then SWIM let's some plain water distill over for 15 minutes or so to be sure nothing is sticking inside the condenser etc and then he has got all the pure freebase out without dealing with the nasty Al/Hg sludge.
Be sure to remove your solvent before steam distilling thoug, since you can't extract the freebase with toluene while the freebase is inside EtOH (toluene and EtOH are miscible!!!).

icecool · Insistent Chemist

Here is the synthesis of 4-bromo-2,5-dimethoxy-b-phenetylamine. Laughing

http://members.home.nl/phenyl/2C-B.pdf

And when steam distilling the Al/Hg sludge there is stuff coming over from 75°C until 90°C what the F*CK is this...
Normally only at 78°C EtOH should come over and at 81-83°C IPA should come over what is the rest?
SWIM stopped it at 90°C and basified it there, hopefully no product is lost now?????????????
Have fun.

P.S There are no pictures of the actual bromination but well the 2C-B.HCl is showed just have a look...

Might there also be someone interested for a GHB synthese with pictures, and amphetamine...

Maybe a better explanation of what´s going on:

I do still have a question about the synthesis, in the pdf I extracted it, but I prefer steam distillation.
Now from 75°C until 90°C something was coming over.
SWIM guesses it's a mixture of EtOH and IPA and water but will there be any product in there.
SWIM saved everything which started to come over from 98°C until 100°C.
SWIM distilled until it was at 99,5°C but now when SWIM continues the distillation (had to stop it since SWIM needed to go to bed) SWIM continued it started again at 99°C and it stays there...
There is quite an oil layer on top of the water which was first brown and now after it had been cold for 12 hours or so it was a clear oil layer, now after heating it up again there is no oil layer visible anymore ofcourse, but SWIM would really would want to know (since with amphetamine freebase that comes over at 98-99°C is this also the same for 2C-H does that also come over at 98-99°C) and won't there be any product in the stuff that comes over at lower then that temperature?
SWIM basified it when I stopped at 90°C everything that came over above that temperature was basified...
It just takes a much longer time as with amphetamine freebase to all come over...
The temperature really stays very long at 99°C now, and now SWIM reduced 10g of nitrostyrene and with amphetamine I reduced 4,8g P2NP.

Hope you someone can help