electrochem reduction of 1-nitroalkenes to amine Success! :)

Bumblebee · Fri Apr 15, 2005 8:36 pm

EDIT: SWIM did it with success last night: read it at the new post now at the bottom

Somebee remembered what it read on rhodium´s a time ago. This bee read similar things in Fester´s Purple Book...
But this poor Bee, has no idea,
what will it have to use, so that it does not lose??? Laughing

Bumblebee · Sat Apr 16, 2005 9:59 am

nobody who has experience with it? is it worthwhile... is it not?
what kind of power source?
I thought it is a good way around Hg-Salts and the contamination Problem.

I had one additional thought...
when i´m distilling off the ethanol along with the ethylacetate, would it not be possible to distill off the remaining acid (H2SO4, Acetic) as well?? so a smaller amount of NaOH would be needed to basify reaction mix, and the whole thing would become more easy to handle...
I am an absolute newbee with not to many options to express what i mean with my traces of english Embarassed

BB

nubee · Master Archiver

can you remeber or find out the name of the book ?? as i feel it maybe available for download...

and yes, i too feel a certain "pull" towards the exploration of electrochemistry... Laughing

Bumblebee · Sat Apr 16, 2005 10:13 pm

Sorry, i talked about Uncle Festers purple book... Embarassed

i meant SOMM (Secrets of methedrine manufacture, sixth edition) by Uncle Fester.
its available for download and to buy.

MargaretThatcher · Sun Apr 17, 2005 5:43 am

I'm a bit sceptical of these Fester electrochemical synthesese. Maybe they work. I don't know. There's that one with the palladium coin and a sheep gut condom. Sounds a bit dodgy to me.

You'll notice that the patent describes a controlled voltage reaction. Depending on the exact conditions, an incorrect voltage will either not work, encourage side reactions or over oxidise/reduce. When you have the thing working according to the patent, it is probably possible to simplify matters and create an exact recipe that works specifying current density applied for a certain time period.

There are lots of instructions for diy reference electrodes out there and it isn't too difficult to make your own voltage controlled source. You could even do it manually first time.

Bumblebee · Sun Apr 17, 2005 9:14 pm

I were a bit sceptical too... thats whay i asked.
But i think it would be no problem to try and give the made experiences to you....

I also don´t trust in everything what i read in "Secrets of Propane, 2-Amino N-Methyl 1-Phenyl manufacture" because some recipes were not tried by the author himself, and are theory or journal articles. But since i know that Fester is originally working as electroplater (respective in that industry), so i trust a bit more in his electrochemical recipes...

The calculation by Fester was made as follows:
Example:
1mol of P2nP
done in a 2500-3000ml Beaker

MargaretThatcher · Mon Apr 18, 2005 2:42 am

If you make or procure an SCE reference electrode, your chances of success will be higher. Thus you have 3 electrodes, the working electrode, the counter electrode and the reference electrode. The voltage is applied between the working and counter electrodes; the reference electrode is used only for measurement of potential difference with the working electrode.

http://www.bioanalytical.com/products/ec/faqele.html

In the patent, they will have used a potentiostat to control the potential difference, but you could do it manually.

Bumblebee · Fri May 06, 2005 9:57 pm

Yeah! Right! Because SWIM has the right do do this legally we did it last night. So i got finally rid of that nasty P2NP i found a time ago.... Wink

I am a simple mind, so i let that thing with the reference-electrode sit aside because it would get too much complicated for me and my abilitys.

first i searched for a good cell divider... the glassing of a porcellain beaker was grinded off with a dremel and used in an attempt just with plain water and some H2SO4 to make it more conductive. the was only 100mA going through the solution... Crying or Very sad

...fucked it up...

Then i did think about the sheeps condom.... didn´t find it anywhere... Sad

then i found out that Cellophane is good for using it as the cell divider, but i lacks of stability. The bags i formed got destroyed in the worm solution, but current passes by very good.

At least i found an little tiny terracotta flower pot without glaze or anithing. This was just perfect it lets through 3-5A with my PC-Powersupply i used.

OK we set it up as follows:
A beaker 1000ml was filled with 300ml catholyte made out of 2 parts EtOH, 1part H2SO4, and one part Acetic Acid (we did use GAA because we had nothing else) it has got the smell of ethylacetate instantly after mixing...
in the catolyte the flower pot (diam:4cm) was placed, and filled with dil. 5% H2SO4.
The P2NP (15g) was stirred into the catholyte which got yelloish couloured.
in the Catholyte was placed the Cathode made out of copper (50mm x 60mm t=3mm) and in the anolyte a piece of graphite (ca 2x2cm and 10cm long).
the Beaker was placed in a water bath on the magstirrer, and equipped with a stirbar.
the electrodes were connected to the 12V output of a PC-powersupply with an amperemeter in line.
the power was switched on an a lot of Hydrogen formed in the catholyte at the cathode. He let it run for 12 Hours @3-4,5A. Anolyte was filled up 2 times with H2O because of the evaporation.
A lot of heat was produced but external cooling with a water bath did it hold in a 40°C area...
after the 12 hours the yellow P2NP colour and the smell was gone, and the catholyte seemed whithe to light light yellow.
the cathode was in good condition but the anode was now just 5mm in diameter where it came in touch with the anolyte, Shocked

.

the formed ethylacetate was destilled out of the solution and we stopped at a temperature of 110°C in the distilling flask (we are both no destilling experts and i hate distillations because make everytime something false and i am not patient enough...) but i think we didn´t became all the etylacetate out of solution.

the residue (about 200ml) was chilled, and made basic with NaOH, and Voila: strong smell of 1phenyl2aminopropane Very Happy

.
a brown oil floats to the top (seemed to be ca 6ml),
the water layer was still yellowish and Ph around 4 so we added some more NaOH-solution and suddenly there were clouds in the water layer and the coulour turned to blue-grey (????), the water was strongly basic to ph-paper, so i stpped adding more NaOH.
200ml toluene was added, and the freebase extracted (there was a lot of bown/greyish mess in the water layer that formed an emulsion as we tried to separate.
the first pure light yellowish toluene layer was collected and a second extraction with toluene was done again... we tried to destroy the foamy emulsion between the layers with some IPA but then a big crystalline mass appeared at the bottom:oops: (what is this???)

toluene was poured off and put to the first extraction we done.
the toluene was washed 3 times with H2O and set aside. It appears as a yellow liquid and holds still a lot of freebase i think, a piece of paper soaked in the toluene and dried at the air smelled like good product Wink

i don´t know if he should try to crystallize it now or after a distillation (you know: no eperts... blah ) since the half of the product will sick to the walls of the dilstilling setup...
i think we ry to dry the Toluene and crystallize once and the recrystallize from___?? ...

so long
BB

thenewrunne · Chemically Balanced

bumblebee! That's just awesome. I was looking for "real" experimental information on the electo-method.

Will you be doing more trials of this? Would you mind putting together a more formal report about it so we have less of a problem following the path you took?

Bumblebee · Sat May 07, 2005 3:23 am

i will first have to figure out what the extraction problems are, otherwise i can´t tell for sure what is better or not in the reaction when the product get lost while extracting... Smile

for sure we try again maybe scaled up a bit.

@thenewrune: what do you mean with a mor formal report? If you mean my english... its not really easy for me to express what i mean and have seen because i have anothe native language. wich part couldn´t you follow. Smile

this was meant as a raw writeup of the experiment. To s how that and how it works.
If i forgot anything... ask Wink

we will try to do this at a lower voltage next time using the 5V 15A Output from the Computer-Power Supply...

the fine thing is that there is nothing in this reaction that can be put on a "watched list". neither the acetic acid nor the sulfuric.... and ethanol and power from your power supply cannot be forbidden.... Very Happy

MargaretThatcher · Sat May 07, 2005 4:27 am

Superb results. Let us know if this gets right through to the finished product and an idea of yield.

Also, depending on the electrode geometry, you have a cathode area of around 30 cm2, giving a current density of around 100 mA/cm2 (half the patent). Be interesting to see how low a current you can go and still get a product. If you draw a voltage/current graph, you might be able to see where reduction kicks in. If you have a cathode with a high enough hydrogen over-potential, you can reduce without getting any hydrogen evolution. Copper may be high enough, I don't know.

Nice one. Smile

Bumblebee · Sat May 07, 2005 6:27 am

should we make the sulphate ore the HCl salt out of it? I think we try making the sulfate with dil. H2SO4 in IPA... dripping it in a nd look what comes out, right?

tom-a-rom-rinbow · Sat May 07, 2005 12:08 pm

very exciting! as fun as the amalgam reactions are i too think the electroreductions deserve more attention. i wonder if these can be scaled more effectively, given that you can directly control the reaction rate and that there are no stirring problems due to sludge... Twisted Evil

i have no experience with amph, but think it can be crystallized directly from toluene by titration with dilute h2so4. i would dry the toluene over MgSO4 or similar first. sometimes adding a 5-10% portion of diethyl ether before cooling will help crystallization.

otherwise hcl gas is easy to generate by addition of hcl to conc h2so4 (be sure to stir or shake after every 1-2ml or these two will form separate layers). but Propane, 2-Amino 1-Phenyl .hcl is reported to be very hydroscopic and hard to crystallize.

thenewrunne · Chemically Balanced

Bumblebee · Sun May 08, 2005 4:39 am

ok.

i will first determine how much yield we got from the first. monday i can buy some drying agents, to get everything waterfree, and i report back how many sulfate it yielded. if I find a way to make it free of H2O with the equipment we already have i do it earlier.

i´m too lazy to distill it first because of the small scale, and since no Hg or other Poisons were used i skip it.
i hope all the pollution will stay in the toluene... i try to vacuumfilter it wash with icecold ipa in the buchner funnel and we will see if it looks white enough. when not, i will recrystallize....

-wich solvent to rextallize Amph-sulfate??

-any suggestions to determine purity? i fear that it is possible that the H2SO4 will form some other salts with reaction byproducts or acetic acid comounds?!? Confused