Sciencemadness Discussion Board - Birch reduction without ammonia

Birch reduction without ammonia

underground - 8-12-2017 at 11:19

I want to know if there is any way to substitute the liquid ammonia in Birch reduction with something more easily available. After searching a bit i found a reduction similar to Birch reduction called Benkeser reduction. Wikipedia says that is uses low molecular weight alkyl amines as the solvent and as a source of protons.

Also will any way of the above reduction be more powerful than the other ? And in general what are their main differences

[Edited on 8-12-2017 by underground]

clearly_not_atara - 8-12-2017 at 11:53

A common modification uses diethyl ether with sodium hydroxide and ammonium nitrate. I believe the patent is titled "Novel dissolving-metal reduction schema".

It's also possible to use ethylamine bp 21 C in an ice bath, only problem is that ethylamine is unpurchaseable (listed) and not easy to make. Decarboxylation of beta-alanine is the OTC route but ketones do not catalyze the rxn and it's hard to collect the product due to its low bp.

arkoma - 8-12-2017 at 12:28

That is the basis for the "shake and bake" reduction of psuedoephedrine. I believe Coleman fuel can be used along with bone dry NH₄NO₃ and NaOH

underground - 8-12-2017 at 13:19

Quote: Originally posted by clearly_not_atara

A common modification uses diethyl ether with sodium hydroxide and ammonium nitrate. I believe the patent is titled "Novel dissolving-metal reduction schema".

It's also possible to use ethylamine bp 21 C in an ice bath, only problem is that ethylamine is unpurchaseable (listed) and not easy to make. Decarboxylation of beta-alanine is the OTC route but ketones do not catalyze the rxn and it's hard to collect the product due to its low bp.

Quote: Originally posted by arkoma

That is the basis for the "shake and bake" reduction of psuedoephedrine. I believe Coleman fuel can be used along with bone dry NH₄NO₃ and NaOH

With this way ammonia is produced (NH4NO3 + NaOH → NaNO3 + NH3 + H2O), so this is actually a Birch reduction. The pressure for the "shake and bake" method is needed to liquify ammonia from ammonia gas that is produced from the above reaction. I dont think so diethyl ether is neccesary for that reaction. It is just a solution of the disolving materials that need to be reduced .

[Edited on 8-12-2017 by underground]

[Edited on 8-12-2017 by underground]

clearly_not_atara - 8-12-2017 at 13:45

Diethyl ether allows the reaction to occur above the boiling point of ammonia by solvating it; this avoids using liquid ammonia, as you asked. I think hydrocarbons might also work as arkoma mentioned.

Melgar - 8-12-2017 at 14:03

@not_atara: Does the patent say anything about a two-liter soda bottle?

IIRC, ethylenediamine works reasonably well here, although it's prone to forming heterocycles and other side reactions.

Also, if you have a bunch of reactive shit at the bottom of the reaction vessel, you're better off using lithium than sodium. Because lithium will float.

arkoma - 8-12-2017 at 15:32

*cough* hydrocarbon solvents work. "Starting fluid" is mostly hexane.

Melgar - 8-12-2017 at 15:51

Quote: Originally posted by arkoma

*cough* hydrocarbon solvents work. "Starting fluid" is mostly hexane.

The fact that ether is a hydrogen bond acceptor certainly works in its favor, as far as dissolving ammonia.

underground - 8-12-2017 at 20:34

Quote: Originally posted by Melgar

Quote: Originally posted by arkoma

*cough* hydrocarbon solvents work. "Starting fluid" is mostly hexane.

The fact that ether is a hydrogen bond acceptor certainly works in its favor, as far as dissolving ammonia.

So if the trick is by disolving ammonia gas into a non-polar solvent, why then pressure is needed ? Also some other eco-friendly solvent (like Limonene) will work ? Unfortunately i cant find any ammonia solubility info for non-polar solvents

[Edited on 9-12-2017 by underground]

Chemi Pharma - 10-12-2017 at 08:15

here's a study about Birch reduction conditions with Lithium and ethylenediamine instead of liquid ammonia, as cited by @Melgar.

They also say that sodium can be used with ethylenediamine instead of lithium, but that's a powerless reduction system and can form polymeric byproducts with naphthalene, for example.

Attachment: lithium-ethylenediamine reducing system.pdf (491kB)
This file has been downloaded 626 times

underground - 11-12-2017 at 02:33

After searching a bit around the forum i saw that it is not necessary to use liquid ammonia, instead gas ammonia will do the trick. I have seen many people here in this forum successfully made the "lithium bronze" by just bubbling ammonia into a solvent (usually Et2O) containing lithium metal. The "Lithium Bronze" looks to be lithium tetraamine (Li(NH3)4). Now some calculations.

Li + 4NH3 --> Li(NH3)4 +1e

Lets assume a molecule Y that weights 200g/mol needs +2e and 1 mol of NH3 to be reduced. So for each mole is needed 2 moles of Li and 9 moles of NH3

Li = 7 g/mol
Nh3 = 17g/mol
Y = 200g/mol

So for each 200g of Y molecule we need 14g of Li metal and I53g of NH3

Gas law says that 1 mole of any gas will occupy 22.4 liters
of volume at standard temp and pressure

Here are my thoughts.
A balloon can easily took 3Liters of air so 3liters of NH3 in gas stage is 2,28g

So a 3L ballon filled with NH3 (2,28g) can react with 0,20g of Li and recude 1,20g of Y

So what now if we put the 0,20g of Li, 1,2g of Y some Et2O and fill it with NH3 ? In theory it ill successfully reduce the the Y material right ?
These ay looks to be quite easy for amateaur chemists rather that dealing with liquit NH3 and Ethylenediamine/Diethylamine

AJKOER - 11-12-2017 at 09:21

Quote: Originally posted by clearly_not_atara

Ethylamine may perhaps be made, among other products, following the path described in this paper ("ADDITION OF ETHYL RADICALS TO ETHYLENE", by J.A. Pinder and D.J. Le Roy, available at http://www.nrcresearchpress.com/doi/pdf/10.1139/v57-085 ) to create the ethyl radical, .C2H5, or perhaps trying a one pot variation avoiding the pumping of gases,...,where dry NH3 is also added to the system.

Suggested reaction path:

Hg(3P1) + H2 = Hg(1S0) + 2 .H
.H + C2H4 = .C2H5
.H + NH3 = .NH2 + H2 (Source: see http://aip.scitation.org/doi/abs/10.1063/1.3605242?journalCo... )
.C2H5 + .NH2 = C2H5NH2

Some other reactions:

.C2H5 + .C2H5 = C4H10
.C2H5 + .C2H5 = C2H4 + C2H6
.NH2 + .H = NH3
.....

Not easy to execute but reagents are available.
------------------------------------------------------

The above is a dated reference (1957) and a more recent work (1964) mentions a path to .C2H5 from the photolysis/heating of C2H6 in N2O claiming to produce the ethyl radical (see http://www.nrcresearchpress.com/doi/pdf/10.1139/v64-401 ), to quote:

"or as the initiation process in the oxidation of molecules which readily decompose into free radicals, such as ethane (2).....

Castellion and Noyes (3) studied the photochemical reaction between nitrous oxide and ethane at temperatures up to 105 degrees. They concluded that ethyl radicals formed in the system do not undergo reaction with nitrous oxide at these temperatures. "

The process may not be as efficient but does avoid the use of mercury vapors. Not sure if if the cited temperature is 105 F or C. My take looking at a 2004 work "Mechanism of the Photolysis of Ethane at 1470 Å" (see http://aip.scitation.org/doi/abs/10.1063/1.1725255?journalCo... ) and higher temperature decomposition research as well (see http://www.nrcresearchpress.com/doi/pdf/10.1139/v66-358):

Primary (85%):
C2H6 --Heat 105,light--> .H + .C2H5
.C2H5 --> .H + C2H4
.......
Secondary (15%):
C2H6 --Heat 105,light--> .CH3 + .CH3
2 .CH3 + 2 C2H6 --> 2 CH4 + 2 .C2H5
.C2H5 --> C2H4 + .H
.....
Also, for both paths:
.R + NH3 --> RH + .NH2
.H + NH3 = .NH2 + H2 (Source: see http://aip.scitation.org/doi/abs/10.1063/1.3605242?journalCo... )
.H + .H --> H2
.C2H5 + .NH2 = C2H5NH2

and certainly other products.

[Edited on 11-12-2017 by AJKOER]

[Edited on 12-12-2017 by AJKOER]

unionised - 11-12-2017 at 10:25

Quote: Originally posted by AJKOER

Quote: Originally posted by clearly_not_atara

So, you think that an impractical method for making ethylamine from ammonia helps solve the problem of doing a Birch reduction without ammonia.

While you ponder that, perhaps you could look at the practical rate of production of ammonia from your scheme- Lets say you have a kilowatt of photons at the right frequency.

clearly_not_atara - 11-12-2017 at 12:45

You've been posting on sciencemadness for fourteen years, and yet you still think it's worthwhile to argue with AJKOER about radical reactions? :p

Thermal decarboxylation of beta alanine is OTC and should be quite easy, although you'll need to pyrolyse a lot of it probably. But turning a stream of hot ethylamine gas into a flask of liquid ethylamine is harder than it sounds.

http://pubs.rsc.org/-/content/articlelanding/1951/qr/qr95105...

unionised - 11-12-2017 at 12:53

Quote: Originally posted by clearly_not_atara

You've been posting on sciencemadness for fourteen years, and yet you still think it's worthwhile to argue with AJKOER about radical reactions? :p

I wouldn't want anyone to think I was a quitter.
(And it seems he only started in 2011)

[Edited on 11-12-17 by unionised]

underground - 11-12-2017 at 13:48

Hey guys what do you think about my above post ? If these will work it will be very simple and easy. To make things even more simple i believe we can use sodium magnesium oxide aggregate instead of lithium.

I dont think so magnesium oxide will do any damage to the reaction or hurt somewhere.

[Edited on 11-12-2017 by underground]

AJKOER - 11-12-2017 at 15:41

Unionised:

Look again, I now have two cited paths to the ethyl radical

.

Note, the first paper focus is not on the extent of the ethyl radical formation, per se, but the results of successive radical collisions creating certain products. For example, the odds of two .C2H5 species meeting up is low, and is different from a .C2H5 meeting, say .NH2, which could be sourced from an excess of ammonia reacting with .R or .H radical.

I have previously cited amine formation via photolysis with extra ordinary results on SM, on a thread that you, apparently, did not participated. Here is an extract:

"Related source (absent the benefical effect of N2O to create more hydroxyl radicals) see K. Ogura, "Photolysis of CH4, NH3, H2O mixture: formation of methylamine and ethylenediamine", in Journal of Photochemistry and Photobiology A: Chemistry, Volume 49, Issues 1–2, September 1989, Pages 53-61, https://doi.org/10.1016/1010-6030(89)87105-9, link: http://www.sciencedirect.com/science/article/pii/10106030898... . Here is the abstract:

"The photolysis of the mixture CH4, NH3, H2O was performed with a low pressure mercury lamp at 100 °C and atmospheric pressure. Of the products, the major nitrogen-containing compounds were methylamine and ethylenediamine; the maximum selectivity of the two amines exceeded 99% in the mol per cent of N-containing products. The other products were methanol, ethane and hydrogen, but the formation of methanol and ethane decreased rapidly with an increase in the amount of added ammonia. This was attributed to the preferential reactivity of methyl radicals with NH2 rather than with OH and/or CH3. The formation rates of NH2, CH3NH2 and NH2C2H4NH2 are discussed."

[Edited on 11-12-2017 by AJKOER]

[Edited on 12-12-2017 by AJKOER]

arkoma - 11-12-2017 at 16:09

Quote: Originally posted by unionised

Quote: Originally posted by clearly_not_atara

You've been posting on sciencemadness for fourteen years, and yet you still think it's worthwhile to argue with AJKOER about radical reactions? :p

I wouldn't want anyone to think I was a quitter.
(And it seems he only started in 2011)

[Edited on 11-12-17 by unionised]

Oh my that was a good laugh after a hard day!

Corrosive Joeseph - 11-12-2017 at 23:39

@ underground - You might like this attachment........

"Reductions with Lithium in Low Molecular Weight Amines and Ethylenediamine"
J. Org. Chem. 2000, 65, 7098-7104

There is also information on the forum about making isopropylamine from glyphosate weedkiller

/CJ

Attachment: Reductions with Lithium in Low Molecular Weight Amines and Ethylenediamine.pdf (122kB)
This file has been downloaded 619 times

underground - 12-12-2017 at 04:16

Ok thank you Corrosive Joeseph for your reply, i will study it

unionised - 12-12-2017 at 12:48

Quote: Originally posted by AJKOER

Unionised:

Look again, I now have two cited paths to the ethyl radical

.

[Edited on 12-12-2017 by AJKOER]

Yes; but nobody asked for even one path.

If someone asks you for a recipe for stew with dumplings would you give a reply involving photolysis and some sort of reactive oxygen free radical?

clearly_not_atara - 12-12-2017 at 13:44

Quote: Originally posted by unionised

Quote: Originally posted by AJKOER

Unionised:

Look again, I now have two cited paths to the ethyl radical

.

[Edited on 12-12-2017 by AJKOER]

Yes; but nobody asked for even one path.

If someone asks you for a recipe for stew with dumplings would you give a reply involving photolysis and some sort of reactive oxygen free radical?

All cooking does start with photosynthesis, after all.

Corrosive Joeseph - 13-12-2017 at 03:32

Quote: Originally posted by underground

Ok thank you Corrosive Joeseph for your reply, i will study it

You are most welcome.

If you really want to study, you will probably also like this attachment -

"Reduction of C=X to CHXH by Dissolving Metals and Related Methods" - J.W. Huffman

Repost, but it is just tooo good.

Mandatory reading on your reaction includes -

"Reductions in Organic Chemistry" - Milos Hudlicky
http://cnqzu.com/library/Anarchy%20Folder/Chemistry/Crystali...

and

"Preparative Organic Chemistry" - Wilgand and Hilgetag
http://library.sciencemadness.org/library/books/Weygand_and_...

See also Melgar's attachment and my post in this thread.
"Reduction with alkali metal and alcohol" - https://www.sciencemadness.org/whisper/viewthread.php?tid=75...

Over and out......

/CJ

Attachment: Reduction of C=X to CHXH by Dissolving Metals and Related Methods - J.W. Huffman.pdf (2.9MB)
This file has been downloaded 519 times

underground - 17-12-2017 at 09:58

After searching a bit more it looks like Birch reduction also needs some source of hydrogen usually taken from alcohols. Will just Et2O provide the hydrogen needed or must be something like ethanol/methanol. Ammonia itself cannot provide that free hydrogen ? Also what if i bubble ammonia into anhydrous isopropyl alcohol ? Will this isopropyl alcohol/ammonia solution be effective for a birch reduction ?

macckone - 17-12-2017 at 12:02

underground, the hydrogen can be donated by the alcohol being reduced since birch is generally used to reduce an alcohol. Residual water can also be a donor, but too much will kill the reaction by converting the lithium to hydroxide without reduction of the target compound.

JJay - 17-12-2017 at 13:17

The Birch reduction is generally used to reduce aromatic rings. While there is a well-known application of it in reducing an aromatic alcohol, that's a special case.

Corrosive Joeseph - 17-12-2017 at 16:27

More PDF gold........

/CJ

[EDIT] - And some...... Extra UL

Attachment: Reduction of C=X to CH2 by Dissolving metals and Related Methods.pdf (362kB)
This file has been downloaded 1004 times

[Edited on 18-12-2017 by Corrosive Joeseph]

Attachment: Partial Reduction of Aromatic Rings by Dissolving Metals and by Other Methods.pdf (4MB)
This file has been downloaded 1449 times

underground - 25-12-2017 at 13:46

Well cause i am still thinking for some OTC available chemicals to substitute ammonia, what if liquid urea will be used ? (Melting point is 133 to 135 °C). Will Li metal form free electones in liquid urea ?

The urea question

Wurfgurf - 8-2-2018 at 08:26

Before I opted on writing this post I checked the date of the last one and couldn't help but be tickled at the fact that on Christmas Day, tree in the room, perhaps kids running around (ok, so maybe he's not Christian and this is a slanted perspective, but the imagery is just classic) present wrappings everywhere with those little bows taped to at least one persons back without their knowledge. Wife asks him, "are you thinking about the gift you wished you had and didn't get?" Hopefully pride or jurisprudence kept the truth from the eyes of the better half. Outside of this, I wish I could tell you with certainty one way or the other. It is a good question. I'm going to put my money on the answer being "no", because I don't get the impression, outside of ammonia content, that urea fits the bill of "amine". Urine is approx 85% urea, if you are dehydrated, and of course there's a range of something like 80-90%, perhaps. 85 seemed like a good "if I'm five percent off I won't get sued for much" presumption. Since I didn't catch the name of the man who posted the reminder and direct connection to those very in depth books, my hats off, and I thank you from the bottom of my heart. I couldn't sleep last night and just as I went to turn off my device I'd see more irresistible information and I'd read a few more, and repeat the last gesture, and then a few more, and so on ad finitum. The battery finally bellowed to be charged at somewhere around 4am and so I relented. I felt like Johnny 5 in short circuit looking for more input! When I said "reminder" I was, of course, referring to the phenomenal library of priceless knowledge unavailable anywhere else I've ever looked. It's every bit as in depth as any college that has a decent premed program, without having to pay. This is a really really awesome forum. For the many of the members that are more knowledgeable in chemistry, in all facets than I am, I look up to you. Thank you so much for sharing the only currency I believe in anymore.

Bert - 8-2-2018 at 09:29

The previous odd, rambling stream of consciousness babble post has caused me to ban Wurfgurf and his other ID (Quessia) registered with an email address of: Wurfgurf@gmail.com

I have no freaking idea what this is about, yet. But after the fairly sane previous 7 posts under this name, it is odd enough to suggest some questions:

Is PhD is off his psych meds again?

Did SOMEONE finally got their Birch reduction down and OD'd in front of their keyboard?

Couldn't I have done something more personally worthwhile with the last 10 minutes of my life?

Quote: Originally posted by Wurfgurf

Before I opted on writing this post I checked the date of the last one and couldn't help but be tickled at the fact that on Christmas Day, tree in the room, perhaps kids running around (ok, so maybe he's not Christian and this is a slanted perspective, but the imagery is just classic) present wrappings everywhere with those little bows taped to at least one persons back without their knowledge. Wife asks him, "are you thinking about the gift you wished you had and didn't get?" Hopefully pride or jurisprudence kept the truth from the eyes of the better half. Outside of this, I wish I could tell you with certainty one way or the other. It is a good question. I'm going to put my money on the answer being "no", because I don't get the impression, outside of ammonia content, that urea fits the bill of "amine". Urine is approx 85% urea, if you are dehydrated, and of course there's a range of something like 80-90%, perhaps. 85 seemed like a good "if I'm five percent off I won't get sued for much" presumption. Since I didn't catch the name of the man who posted the reminder and direct connection to those very in depth books, my hats off, and I thank you from the bottom of my heart. I couldn't sleep last night and just as I went to turn off my device I'd see more irresistible information and I'd read a few more, and repeat the last gesture, and then a few more, and so on ad finitum. The battery finally bellowed to be charged at somewhere around 4am and so I relented. I felt like Johnny 5 in short circuit looking for more input! When I said "reminder" I was, of course, referring to the phenomenal library of priceless knowledge unavailable anywhere else I've ever looked. It's every bit as in depth as any college that has a decent premed program, without having to pay. This is a really really awesome forum. For the many of the members that are more knowledgeable in chemistry, in all facets than I am, I look up to you. Thank you so much for sharing the only currency I believe in anymore.

[Edited on 8-2-2018 by Bert]