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pauldir
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... first " HELLO COMMUNITY ! "
(my english is bad ..)
@ TheCopperMan
you say we must check the ph from the steam destillation. Where must i check the ph correctly ? In the reaction flask or in the flask with the amine
freebase + water
(after the steam destillation, the freebase swim on the top of water when it cooled)
for my understanding, when i do a steam destillation (easy way) i fill my reaction flask with NaOH, that i get a ph ~12, then i start heating ~ 100°C
for boiling.
The water takes the freebase with the steam to the outher flask (when i start, this flask is empty  ), from time to time i add some more lye to the reaction flask
(ph must about 12 here). Where can i now see it is finished ? All freebase is gone ?
i hope you all can help one more nooby. thank you and have a nice day !
[Edited on 17-8-2014 by pauldir]
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TheCopperMan
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@crystal
No attempt with Ga-salts yet, only Ga metal and it works pretty good. See http://www.sciencemadness.org/talk/viewthread.php?tid=31127
@pauldir
Check PH of the distillate, it should be basic, indicating amine. Then simply add acid until neutral and evaporate the water.
As for knowing when all freebase has distilled over, you need to occasionally check the PH of the drops as they come over. Once the drops coming over
are neutral or close to it, all amine has been distilled over.
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pauldir
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thank you @TheCopperMan
..... ahhh i hope i understand now. The NaOH alone comes not over because it is dissolvably in water. Right ?
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lullu
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The NaOH will not end up in the receiver.
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solo
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....the method with cooper sulfate and sodium chloride was tried as posted , after adding the dissolved copper sulfate and sodium chloride the
reaction was violent and made an impressive volcano trowing out most of the aluminum....I had a catch plate and return all the material back in and
continued with the process .......
i was not able to get much back since i saw most of the aluminum when i filtered......next time when i try it with mny beta nitrostyrene i will heat
the solution then pour in in a bucket and then add the copper sulfate and sodium chloride and let it rise as much as it wants since the polypropolene
will take quite a bit heat ....
once it calms down i will pour it back in my flask and continue with the reaction or use a RBF ten times head space and run the reaction with no fear
of volcanoes ocurring and perhaps the reaction will run its course without andy interruption....solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Templar
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I tried this reaction as per the writeup from copperman. I made sure I followed it very closely. I let it reflux for 24hrs after the initial reaction
had died down.
After basification and extraction with toluene, I received no yield.
I have to try it again, but I am viewing this synthesis with a heavy dose of skepticism. The internet appears to be full of writeups that promise a
lot and give nothing... although it is yet to be seen if this is undoubtably the case...
The fact that no one else has succeeded with this reaction except copperman is worrying.
It will be very dissapointing if it doesnt work a second or a third time, and if no one else can confirm results 
Please note, I'm not saying it doesnt work yet, I'm just saying that it isnt promising when it is run with pure reagents closely following the
writeup, and doesnt give anything, and when even nitromethane hasnt been successfully reduced from other members reports.
The substrate in question was a dimethoxylated nitrostyrene.
He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into
thee.
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pepsimax
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The reaction definitely does work, with beta nitrostyrene at least but I can't get consistent results.
There are two main issues I think....
A, stirring. It's hard to keep the Al under. My best results are when, by luck, the egg bar managed to hold it all down. Overhead stirring is best.
But, I made a galluminium alloy which sank when broken up, this worked perfectly with copper chloride.
B, temp. I feel there's a point where if the temperature drops below, the reaction dies and won't restart. Unfortunately it seems to be very close to
the bp of ethanol. My highest yielding runs have been very violent and the solvent has boiled away. When I kept the temp stable below 72 in the
initial reaction i got no product.
Maybe a higher bp solvent would help, n-PrOH? I can't seem to find any but it looks a good candidate to me, primary alcohol,protic bp 97'c
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Templar
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Quote: Originally posted by pepsimax  | The reaction definitely does work, with beta nitrostyrene at least but I can't get consistent results.
There are two main issues I think....
A, stirring. It's hard to keep the Al under. My best results are when, by luck, the egg bar managed to hold it all down. Overhead stirring is best.
But, I made a galluminium alloy which sank when broken up, this worked perfectly with copper chloride.
B, temp. I feel there's a point where if the temperature drops below, the reaction dies and won't restart. Unfortunately it seems to be very close to
the bp of ethanol. My highest yielding runs have been very violent and the solvent has boiled away. When I kept the temp stable below 72 in the
initial reaction i got no product.
Maybe a higher bp solvent would help, n-PrOH? I can't seem to find any but it looks a good candidate to me, primary alcohol,protic bp 97'c
|
I used a large stir bar and aluminium turnings. Kept reaction rate consistent and under control. Works well for Al/Hg.
What yields have you gotten so far?
He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into
thee.
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pepsimax
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Well, with al turnings I got 0. Try with large flat strips like coppwrman suggested.
Yields have been 0-75%, sorry that isn't much help! Following the orginal post I always get something, though the side products vary in identity and
quantity greatly. Your substrate must be very pure or side reactions compete...
When you have large flat strips you can see the copper plating on to it, I see that as a good sign, never had a complete failure like that.
Have you got any gallium? Look in coppermans other thread and try what I posted with copper chloride, works every time and is very clean!
Ps- what solvent did you use? Ipa doesn't work, ethanol or methanol does. Replicate the original post and I think it will be unlikely you won't see
product.
[Edited on 18-8-2014 by pepsimax]
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pauldir
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| Quote: Originally posted by pepsimax |
Have you got any gallium? Look in coppermans other thread and try what I posted with copper chloride, works every time and is very clean!
[Edited on 18-8-2014 by pepsimax] |
in a smal test, this was the same here. First test only with al/ga, the reaction will not realy start, than i add some copper chloride and the
reaction looks great for me. now i need some gallium for real testing
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pepsimax
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Excellent, glad to hear one of my suggestions helped! Let us know how it scales, I've run out of gallium too!
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Templar
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Hmm I will try the aluminium strips then. It seems very strange though that Al turns would not work.
He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into
thee.
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pepsimax
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Good luck. Make sure to let it run as hot as possible whilst keeping it in the flask. If you still don't have any luck, the gallium/al/copper method
will work in that scale, but you'll probably have to tweak it for large amounts
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TheCopperMan
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Templar : Did you try a regular Al/Hg on the styrene?
If a regular Al/Hg doesnt work then odds are Al/Cu or Al/Ga wont work either.
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pauldir
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@TheCopperMan
is it possible that you post some pictures from the work, step by step suitable to your first postings ? (use a tool like Exif Tag Remover for erase
metadata from pictures)
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Templar
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Yes the nitrostyrene was well purified, light orange xtals.
A more cimprehensive writeup would likely help
He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into
thee.
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Crypto
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I can confirm that it works. I haven't had luck when I tried to reduce nitromethane but I did reduce b-nitrostyrene. I would not say that I was
successful, because the yield was really low. I have to say thou that I just wanted to do a little test and I didn't make much effort. After some
optimization of the procedure, the Al/Cu couple can be really useful.
Anyway this is how it went:
I mixed GAA, IPA and water. 100, 35 and 35 ml of each respectively. To the mixture I added 10 grams of CuCl2.H2O and heated it until most of it
dissolved. To that I added 12 grams of freshly prepared and still wet (after the water wash) crystals of b-nitrostyrene. I can't tell how much of them
there was really. I estimate that something between 6 to 10 grams, closer to 6 I think. After it all went into solution I threw in 10 grams of thick
(1mm) Al ribbon. The temperature rose until reflux and kept at that level for 10 or 15 minutes. After it started to drop I just left it and went to
eat dinner  No stirring or reflux was applied. After maybe an hour I basified
everything and extracted an astounding yield of about 800mg. Loads of unreacted crystals were on the bottom of the flask. 5 grams of aluminum did not
react as well.
My thoughts on it are:
- IPA can be used
- stirring and keeping under a reflux would probably increase the yield and the consumption of Al
- the yield would still suck (it would probably be around 1600mg)
- elemental copper present in the post reaction mixture was clogging my separatory funnel which was really annoying
- GAA may not be the solvent of choice for this reaction. Polsaer used only GAA and water, and got lower yields than I did. I used mostly GAA and some
IPA with water, and the results were a little bit better. Maybe running it in a mix of mostly alcohol, without acetic acid, would give even better
results. CopperMan used 300ml EtOH, 120ml water, 45ml GAA and claims 70% yields.
- the amount of copper salt needed to activate a certain amount of Al has to be determined.
- the amount of Al/Cu needed to reduce a given amount of substrate needs to be determined as well. I personally do belive that yields around 70%
percent can be achieved but the amount of Aluminum and Copper used in the original procedure seems too low. Copper has lower overpotential for
hydrogen evolution than Mercury so a lot of it can probably just reduce water instead of the substrate. Also more of the Aluminum is turned into AlCl3
because more chloride salt is used to activate it.
- copper doesn't stick to Aluminum like Mercury does when it forms an amalgam. It falls off not long after it plates the surface of Al. That leads me
to think that using thin aluminum with a well balanced amount of a copper salt (enough to plate it but to little to consume it by the formation of
AlCl3) could give better results than using thick metal and big amounts of salts.
Lastly I want to say that I'm not a scientist but a hobbyist and most, if not all, of my assumptions can be incorrect. Thank you.
[Edited on 24-8-2014 by Crypto]
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pepsimax
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Glad to hear it. Bit scared of copper salts myself, apparently they're incompatible with NM. Know any more?
I just condensed some 3,4-dihydroxybenzaldehyde with nitromethane. Will I have dopamine once it's reduced? By Cu/Al of course ...
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Crypto
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Apperently Copperman tried it without GAA and got worse results. Maybe just a little is needed. Unfortunately no one can reproduce his results.
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the gay doctor2
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Hello, I have been watching this thread with great interest.
In reply temple, I reduced 2,5-dimethoxynitrostyrene to 2C-H in good yield. The styrenewas also of terrible quality. 4g was reduced to around 3ml.
Cu sulphate and salt were added originally, then another few grams of Al and cu chloride added when it died down.
I think the copper salts may damage the product. Once the reaction was ready for reflux I carefully added zinc dust. This is very foamy and
exothermic.This quenches the excess copper chloride, then you must steam distil out your freebase. Yeild was extremely high, I'm not sure how much
exactly as my styrene was brown and impure.
I was expecting nothing, got 3ml which was brominated to some sublime 2C-B. The zinc trick also helps with phenyl-2-nitropropene, though yields are OK
with that anyway.
P2NP - CuSO4 50-60%
P2NP - CuSO4, then extra Al
nd CuCl, Zn before reflux - 78%.
There's no way you're extracting the zinc mess efficiently without distillation so don't
waste your time.
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Templar
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| Quote: Originally posted by the gay doctor2 | Hello, I have been watching this thread with great interest.
In reply temple, I reduced 2,5-dimethoxynitrostyrene to 2C-H in good yield. The styrenewas also of terrible quality. 4g was reduced to around 3ml.
Cu sulphate and salt were added originally, then another few grams of Al and cu chloride added when it died down.
I think the copper salts may damage the product. Once the reaction was ready for reflux I carefully added zinc dust. This is very foamy and
exothermic.This quenches the excess copper chloride, then you must steam distil out your freebase. Yeild was extremely high, I'm not sure how much
exactly as my styrene was brown and impure.
I was expecting nothing, got 3ml which was brominated to some sublime 2C-B. The zinc trick also helps with phenyl-2-nitropropene, though yields are OK
with that anyway.
P2NP - CuSO4 50-60%
P2NP - CuSO4, then extra Al
nd CuCl, Zn before reflux - 78%.
There's no way you're extracting the zinc mess efficiently without distillation so don't
waste your time. |
Well done.
So you did the reaction with half the needed aluminium at the start with all the nitrostyrene in solution, then added another half with some more Cu
and sodium salts once it had died down?
Then you added Zn once the reaction reflux was complete and then steam distilled by adding water to the post reaction mix, basifying then just boiling
it in a distillation setup?
Would you be able to go over your exact procedure as best as possible? Amount of Aluminium at the start, type of aluminium etc? (foil, turnings?)
He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into
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the gay doctor2
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Hello friend.
I added 5g Al, thick good quality cut into 30 mm2 squares. 4g styrene, 20ml GAA, 150ml MeOH and 30ml water were brought to 70c.
This stirred via large ptfe paddle at high speed in a 1 litre RBF.
After 15 minutes 2.5g CuSO4 and 5g NaCl, dissolved in enough hot water, was added to the reaction. Within seconds an extremely hard reflux began,
stirring was kept high and heat turned off. The temperature was carefully monitored and as it began to drop, heat was reintroduced carefully to keep
the hard reflux. This shouldtake under 15m to reach.
Now, 750mg CuCl was again dissolved in minimum hot water, 2g of the Al was added and the copper solution as quickly as possible once the Al is in. You
may need to reduce the heat for a few mins but still maintain hard boiling.
Once that has died down let stir at 75 for 30 mins. Now add small spatulas of zinc powder until it has all reacted and stopped foaming and getting
hotter. I'm not sure how much Iused sorry,just a slight excess of what was needed.
Now reflux for one hour or so. After this filter the unreacted metals, then set up for distillation. Boil off the alcohol,basify, then steam out your
product.
There is probably an excess of Al, perhaps reduce the initial portion like you said.
[Edited on 11-9-2014 by the gay doctor2]
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Crypto
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I'm curious how would the system work with imines. I was planning to give it a try but I haven't got anything to reductively aminate right now.
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organichem
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In-situ reduction of ketone/nitroalkane didn't work for me - I only got aminoalkane
Perhaps with pre-formed imine the reaction works?
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TheCopperMan
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| Quote: Originally posted by the gay doctor2 | Hello, I have been watching this thread with great interest.
In reply temple, I reduced 2,5-dimethoxynitrostyrene to 2C-H in good yield. The styrenewas also of terrible quality. 4g was reduced to around 3ml.
Cu sulphate and salt were added originally, then another few grams of Al and cu chloride added when it died down.
I think the copper salts may damage the product. Once the reaction was ready for reflux I carefully added zinc dust. This is very foamy and
exothermic.This quenches the excess copper chloride, then you must steam distil out your freebase. Yeild was extremely high, I'm not sure how much
exactly as my styrene was brown and impure.
I was expecting nothing, got 3ml which was brominated to some sublime 2C-B. The zinc trick also helps with phenyl-2-nitropropene, though yields are OK
with that anyway.
P2NP - CuSO4 50-60%
P2NP - CuSO4, then extra Al
nd CuCl, Zn before reflux - 78%.
There's no way you're extracting the zinc mess efficiently without distillation so don't
waste your time. |
Hi
That is a very high yield. When you got the 78% yield after it was steamed out, did you afterwards vacuum distill the amine to confirm it's purity? Or
just add acid and boil down?
Also maybe you could try it without CuSO4 / NaCl, instead just add small amnts of CuCl2, it should work similarily and produce a similarily hard
reflux. You would save a lot of copper and salt which when scaling up can be pretty crazy to use so much copper per mole substrate.
Like the Zn idea also. Refluxing for long time seems to actually reduce the yields somewhat, and produces some reddish stuff, so this guess indicates
that the copper indeed attacks the amine or substrate or whatever. Adding ZN would help with this.
[Edited on 25-10-2014 by TheCopperMan]
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