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

bio · Working Bee

.............-any suggestions to determine purity?.........

Propane, 2-Amino 1-Phenyl dl (means racemic) Sulfate

Melting Point 280-281 (FYI Dextro isomer >300)
Will be depressed if impure somewhat proportionally

Density 1.15 (25/4)

BTW great work and a few more experiments should give you a current yield and density which is optimum and this will simplify the procedure. Perhaps do some patents searching for similar type reactions for clues of the optimum current density which will allow a more painless scale up.

If you need any help or with the write up just holler!

QuickFitAbuser · Quality Control

Hhmm, very interesting, being an old sheep Gut condom abuser from way back, and with an interest in coulombs, this is Very good reading.
Would like some more exact info on your electrode size vs current, but I get the general idea, and it would appear to work with a high efficency.

Good Work, bumbleBee.
BioAssay pending?

MargaretThatcher · Mon May 09, 2005 5:04 am

What is needed is to determine the actual working electrode voltage wrt a standard reference electrode. However, if the reaction works with the described conditions, it probably isn't too sensitive to voltage: as long as the PD is high enough, it will work.

If you have a high hydrogen overvoltage electrode, you might just be able to turn up the voltage until hydrogen starts to be evolved and then reduce the voltage a little. The reaction proceeds without hydrogen coming off. This would be a good way to set the voltage.

Bumblebee · Wed May 11, 2005 3:15 am

I crystallized the freebase today...
The freebase stands now for 3 or 4 days around in some toluene and i bought some MgSO4 and dried for 1 hour, and filtered.
i dripped in dil. H2SO4 in IPA but no crystals appeared. i checked PH with some wet Ph paper and it was still basic. I continued dripping in the diluted acid solution until the ph was around 8. Then i tried to use a electronic PH-Meter to determine the correct PH. I didn´t know if it works in nonpolar, but i tried anyway, and it showed a stably PH of 8,7 and wasn´t tilling around.
I added dil. sulfuric until Ph was 6,4.
I concentrated the solvent in an aspirator vacuum, until some yellow oil climbed up on the side of the flask, the rest got evaporated and i was left with ca 3-4 (estimated) ml oily crystalline mass at the bottom of the flask. i treated with some cool diethylether and nearly the complete oil seemed to crystallize...
the big lumps were broken up with a glass rod, swirled and the ether sucked off in a buchner funnel.
after drying there were 4,6g of almost white chrystals with a strong benzedrine smell.
Bioassay confirmed success... Very Happy

it is not that much of Product i thought i would get out of the pooled extracts, but it is alright for the first attempt.
what has done to improve this?

next time i will think about using less Voltage (use just the 5V out from PC Supply).
while the 12V out from those Pwrsupplys will give you up to 5 A the 5volt output serves you with up to 15 A.

and i think a better cooling is needed in the process due to the heat that the current produces.

IndoleAmine · Dreamreader Deluxe

If you mean your strange precipitation/crystallization technique, you could take ideas for improvements from here...

Otherwise excellent work.

MargaretThatcher · Sat May 14, 2005 4:09 am

I think one thing you might try is to keep the hydrogen overpotential of the cathode as high as possible, otherwise the hydrogen production which you describe competes with the reaction.

You could try a different cathode. Also, keep the electrode as smooth as possible (highly polished) and the temperature as low as possible.

icecool · Insistent Chemist

Shouldn't chemicals that are being dried with MgSO4 be dried for at least 12 hours?

Bumblebee · Sun May 15, 2005 4:34 am

Guest · Sun May 15, 2005 6:54 am

bumblebee,

Very encouraging results, and well done,

This is certainly of great interest to alot of members here,

Yes, I remember in 1999 or there abouts when the hunt was on for Natural Sheep Condoms, for the fester Palladium Special

It is fascinating to see actual real world resluts on the electrochemical reactions such as this,
Getting the nitro compound to the amine, has always been close to the hearts of many bees, and well done, for showing another alternative,

Great Post, and I am sure that some basic tweaking will lead to better yields, and success for all those that want to use this method,

Keep up the good work, and if you like, you can send any of our mods, a copy of a complete write-up, and we can start to get these perfected methods well documented,

Synthetika

MargaretThatcher · Sun May 15, 2005 5:16 pm

This is a real breakthrough. I wonder what the yield would be with MDP2NP. Also, lead might be a better working electrode (mercury would be the best from hydrogen overpotential considerations).

Vitus · Psychoscientist

Good info on modifying a PC power supply is to be found here:

http://cma.zdnet.com/book/upgraderepair/ch08/ch08.htm
http://www.qsl.net/i0jx/pcsupply.html
http://www.marcee.org/Articles/PCPowerSupply.htm
http://www.mattsrcstuff.com/PCPS.htm

My old 80286 power supply carries a maximum of 15A at +5V and 5.2A at +12V. The newer ATX systems are much more interesting as they also carry a 3.3V line, and are capable of drawing much more current. Take a look at what this one can pull: http://www.maxpoint.com/home/products/pow_supp/spec_pg/whisper2_2_0/

MargaretThatcher · Tue Jun 14, 2005 4:16 am

Vitus · Psychoscientist

Mmm, sort of like a lead anode in an undivided cell with lead acetate in dilute acetic acid?

Lead amalgam is indeed a good idea for a high overvoltage cathode.
This is from US4457814:

"In general, any metal with a higher hydrogen overvoltage than the potential for the reduction of terephthalic acid to p-hydroxymethylbenzoic acid is suitable for the cathode. Examples of materials forming the cathode are mercury, lead and amalgams, alloys of lead with cadmium, antimony, tin or bismuth, and amalgams of lead and lead alloys. An amalgam cathode is prepared by abraiding in a suitable manner the surface of the solid cathode to remove any metal oxidation and then contacting the abraided metallic surface with mercury to form the amalgam. In the case of lead, it is sufficient to abraid the surface of the lead solid to remove all forms of lead oxide and any other impurities. Liquid mercury of 99.9% purity is used as a bath for the abraided solid-lead cathode. In the case of lead, the lead amalgam is formed in the surface of the lead at room temperature upon contacting the mercury bath."

Another point of importance is the cooling of the anode. If this is not done, using 4 Amps of current, the anolyte will heat up considerably (70°C and higher). When a lead anode is used it will get attacked by the acid at these temperatures, forming a layer of lead sulphate that will seriously decrease the current flow. A coil of plastic tubing around a lead cylinder, and an aquarium water pump that constantly pumps water through the tubing keeps the temp relatively stable around 40°C.

For the diaphragm, try Henry Watson's Original Suffolk Candlestick, "Ideal for Use at Home or on Safari". It's a clay cilinder of 2.5 cm diameter and around 15 cm in height. I, say, old chap, jolly good clean fun. Wink

MargaretThatcher · Thu Jun 16, 2005 4:08 am

bio · Working Bee

Another DIY membrane I've had good results with are the bags around the plates found in higher quality car type batteries. The maintenance free type seem to have the sturdiest ones that last quite some time even at elevated temps.

They can be formed by heat sealing or glueing the edges to surround the elctrode or made as a removable divider on a removable plastic frame. Better yet the battery boxes already have dividers into which a window is cut for the mambrane.

Sure wish I could find some Nafion scraps!! Fat chance at $3-500 per sq ft for the thicker Nafion.