Sciencemadness Discussion Board - Best route to Sodium Methoxide

Best route to Sodium Methoxide

Sedit - 1-5-2011 at 20:40

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I have a need for NaOMe but I don't know what the best way to aquire this(don't say buy, thats not my style).

I have attempted to place 25 grams of NaOH in 100 grams of MeOH and refluxed until it all dissolved. I then added an excess of MgSO4 in hopes of pushing the equilibrium as much as possible to the desired compound but after refluxing with what was more then likely way to much MgSO4 I was left with a slush as it appeared the solution wanted to solidify or something. I added a bit more MeOH and filtered a small amount of MeOH solution off and evaporated it almost to dryness. On cooling small crystals appeared in the otherwise clear solution which appear to be either plates or needles, possibly a hybrid of both but I haven't examined them very closely yet. I still don't know if this was successful or not but time will tell and for now its been sealed up until I can work with it further.

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All that said and done other then adding Na or its hydride to MeOH what would be the best way to Sodium Methoxide?

My mode of thinking right now is to add some sort of drying agent to the mix to dry it as evident by the above post. However I fear this will not be complete enough. A couple of ideas I wish to test would be drying it with either Magnesium or Lithium.

Given that its going to be used as an electrolyte in the Kolbe electrolysis a small amount of other Methoxide should not pose much of an issue.

I have looked around but it does not seem that there is any threads on Methoxides around mostly focusing on Ethoxides which allow for azeotropic distillation to remove the water.

Im open and welcome to all suggestions.

Thanks for your time,
~Sedit

symboom - 1-5-2011 at 21:58

well you said you have sodium hydroxide you could make sodium from that melting it with a propane torch i dont own this video but found it and its helped me make my own sodium and even sodium peroxide
http://www.youtube.com/watch?v=rL1cKb3_ojE
and as you said All that said and done other then adding Na or its hydride to MeOH what would be the best way to Sodium Methoxide?
with sodium metal hope this helps

[Edited on 2-5-2011 by symboom]

Panache - 2-5-2011 at 05:20

when i have done this, na into meOH, i never got a completely clear solution until klute suggested an argon blanket, this worked and you can get perfectly clear NaMeO in MeoH.

Sedit - 2-5-2011 at 05:22

I agree that would be best but im lacking Sodium for this practice.

Would Lithium Suffice given that its primary goal is to become an electrolyte? Will Lithium in MeOH turn into the Methoxide? I have heard others suggest it wont.

What about electrolysis of NaOH/MeOH solution to remove the water? Using carbon electrods this seems possible.

[Edited on 2-5-2011 by Sedit]

spong - 2-5-2011 at 06:21

I don't see why Li in MeOH wouldn't form the methoxide, after dismantling a battery and not really wanting to just dump the Li in water I put it into methanol (tech grade, not dry although probably not that wet). It bubbled H2 vigorously and boiled, eventually dissolving, now I have a clear solution with a small amount of white sediment at the bottom (LiOH?) If that's not LiOMe in MeOH then what else could it be?
Suggest a test for the presence of the methoxide and I'll do it, I have no other use for the stuff.

smuv - 2-5-2011 at 07:22

Why not magnesium?

Sedit - 2-5-2011 at 07:53

Magnesium Methoxide or why not use it as a drying agent?

I don't know the solubility of Magnesium Methoxide or I would use it. I can't see it interfering to much in the process. As a drying agent I mentioned my desire to try that.

smuv - 2-5-2011 at 12:43

If you just need an electrolyte, yes why not magnesium methoxide. Magnesium is readily available, reasonably cheep and dissolves easily in methanol (I never use I2 or anything and have good results with HEET straight from the bottle).

dudadiesel on ebay carries sodium methoxide solutions; also lithium methoxide exists.

Although, if you don't tell us what you are doing it is hard really help you (hence my initial one-line response). Its probable that you can get by just fine with sodium hydroxide in methanol if all you are doing is electrolysis.

Sedit - 2-5-2011 at 13:14

Kolbe electrolysis of Glycine along with a number of other experiments as long as that goes as planned. Sorry for not clearing that up, I posted what I was attempting in the short question thread.

If I can get it working it would open the doors to many chemicals over the counter that are not normally avalible.

I think Magnesium Methoxide would work here but I have no references to its use. Everything is NaOMe based.

[Edited on 2-5-2011 by Sedit]

smuv - 2-5-2011 at 15:43

I don't see why you couldn't use NaOH in methanol for this application.

Can't help you with protecting groups though

. Some amino acids are available as their acetates though (google acetyl tyrosine for ex.) although this protecting group won't be all that stable under your reaction conditions...

Sedit - 2-5-2011 at 16:37

Free OH can lead to replacing the Carboxylic acid with an Alcohol grouping followed with reactions with the radicals leading to ethers instead of undergoing the desired radical coupling hence one of the reasons water is being avoided in this reaction. There are some forms of it where NaOH in Methanol is ok but im trying to get it to a more universal means where Methoxides are prefered.

Im curious if the protecting group is needed but I would think I would find out really quick as experimenting is started. I mainly want a protecting group because it would prevent these radicals and the electrods from attacking the nitrogen in anyway.

[Edited on 3-5-2011 by Sedit]

The WiZard is In - 2-5-2011 at 18:53

Quote: Originally posted by Sedit

<hr>
I have a need for NaOMe but I don't know what the best way to aquire this(don't say buy, thats not my style).

Me The Analogue Guy again. My favorite place is the library. Any rate....
detailed syntheses of sodium methoxide using sodium -
methanol - &c dobe in — Organic Syntheses Collective Volume I.
Page 219-20. There is a remote chance I may scan it....?

The good old Merck Index 14th ed. refs Burness, Org. Synth,
39, 51 (1959) I do not have access to this.

[Edited on 3-5-2011 by The WiZard is In]

Sedit - 2-5-2011 at 18:56

I know it can be produced with ease using Alkali metals but I have none other then Lithium. Magnesium will more then likely work and I am going to try this out either tonight or tommorow.

smuv - 2-5-2011 at 19:13

scratch the oxide off of the magnesium by grinding with a mortar and pestle before use (if you want to avoid using a catalyst) to get the Mg to dissolve faster. You should try a test tube experiment before you try the real deal. You can't make super concentrated Mg(OMe)2 solutions because the methanol begins to gel. Mg methoxide is hard to isolate (again it likes to gel) and even then it does so with a few (3 I think) methanols of crystallization.

Good luck. Maybe post some refs (for kolbe)?

Sedit - 2-5-2011 at 19:46

I did that about two weeks ago just for shits and giggles and was shocked how fast the Mg was taken up. I really expected it to be much slower.

Most text state only a 5% solution of Sodium Methoxide for the electrolysis so I can't see gelling being a real issue.

As far as the references go, here is what I have so far along with more Iv been meaning to upload here, If you have anymore feel free to add. No matter what the substrate if its about the Kolbe I could learn something from it.

Kolbe References: http://www.sciencemadness.org/talk/viewthread.php?tid=14705

The WiZard is In - 3-5-2011 at 06:52

Quote: Originally posted by Sedit

<hr>
I have a need for NaOMe but I don't know what the best way to aquire this(don't say buy, thats not my style).

From Organic Syntheses : Collective Volume I

symboom - 3-5-2011 at 23:36

maybe do electrolysis of sodium hydroxide in pure methanol most water removed. forming sodium metal that should react with the methanol as it is formed.

also getting lithium metal i took pipe-cutter (being careful not to crush the casing) to lithium disposable battery. use to do that before when i needed an alkali metal much cheaper to electrolyze sodium from sodium hydroxide

NaOMe oSoEasy

SmashGlass - 19-5-2011 at 07:08

The best way to making sodium methoxide is dry methanol and sodium metal.

Obviously do not (DO NOT) just chuck large chunks of sodium into methanol and stand back with a fire extinguisher and your preferred method of prayer... It will take a bit of planning and cooling.

From the thread so far it was getting fairly intricate already with electrolysis etc...

If you only have NaOH and not Na (s) the elemental metal, one may use electrolysis for this conversion. It was first done in home labs in the 1950's as far as I know but probably earlier in non English speaking countries (ie Germany). They were damn good chemists back then, and still are today. But if you can get your hands on sodium metal in oil much better. Just wash it off with light petroleum ether (and then diethyl ether if you want it super clean). Do this relatively quickly as the freshly cut sodium will quickly oxidize forming NaOH on the surface.

Once you have sodium metal it is a matter of simply adding small amounts of it to dry grade methanol, whilst cooling and keeping it all void of water.

If you just use NaOH in methanol you will invariably make one hell of a mess, which is much harder to dry than the above described general procedure.

And as always Sodium metal is extremely flammable when added to water in small quantities and Explosive in large quantities! I generally kill off the waste sodium (less than half a gram but chucking it in a 10 L (5 gal) bucket from a distance just to see the fireworks and hear the big pop!

Good luck

apischem - 29-7-2011 at 21:18

Na metal + MeOH in RT,stirred until Na disappear, Concentration MeOH

[Edited on 30-7-2011 by apischem]