Tetramethylammonium hydroxide

[encipher]

Hi,

 

Does anyone have any ideas regarding the synthesis of tetramethylammonium hydroxide [ce]N(CH3)4OH[/ce] ?

 

I can't seem to be able to find a supplier of it, since nowadays restrictions are horrible here in the US.

 

Thanks

[RyanJ]

As always the safety stuff: http://www.jtbaker.com/msds/englishhtml/t1820.htm

 

Other than that there seems too be very little about the compound (a lot of cruff on Google). What information are you looking for exactly?

[encipher]

Yeah, MSDS is a good idea =D

 

I'm looking for any ideas on how I can synthesize the compound at my home lab, or possibly at a laboratory if needed (I can get access if needed). I couldn't find much on it anywhere, not google, not wikipedia. I mean it must be snythesized SOME way, wondering if anyone knows how, or can point me in the right direction.

 

cheers

[woelen]

One synthetic route is the use of tertiary ammines (in your case N(CH3)3), which are alkylated with alkyl iodide. For you the following would do.

 

N(CH3)3 + CH3I ---> [N(CH3)4](+) + I(-)

 

Unfortunately I am afraid that the reagents for this are equally difficult for you to obtain. What you could try is obtaining triethylamine. That is a compound which is somewhat easier to obtain. I have some of that compound. It is a nasty compound though, which is liquid, volatile and very irritating. I have no clue where to obtain CH3I. The latter is an extreme methylating agent and as such is extremely dangerous. It is very potent, it methylates your DNA, and that is not good at all!

 

It is funny to see that a fairly benign compound as a quaternary ammonium salt can only be prepared through the use of really nasty reagents. I myself would not try to do this in a home lab, to my opinion the reagents are too toxic.

[RyanJ]

I'm not sure about buying iodomethane but you can certainly make it.

 

Warning: I have not attempted this reaction and looked it up in a textbook. The reaction is exothermic and I DO NOT recommend trying it as it may be dangerous to do so.

 

[ce]5CH3OH + P + 2 \frac{1}{2}I_2 -> 5CH3I + H3PO4 + H2O[/ce]

 

However you would probably need to distill the iodomethane off and remove the excess iodine.

 

Another reaction I turned up was the addition of dimethyl sulphate too calcium carbonate in aqueous potassium iodide.

 

[ce](CH3O)2SO2 + KI -> CH3I + CH3OSO2OK[/ce]

 

Apparently both have high yields industrially I would probably think it would be produced in a similar way too chloromethane, methane in an atmosphere of chlorine under UV light leaving too free radical substutution although it will probably be far less vigorous than that of of chlorine.

 

Also, just to re emphasize what Woelen said, iodomethane is an irritant and toxic if swallowed so don't try any of these reactions without the correct safety apparatus and experience.

 

Edit: Woelen, wouldn't iodomethane be quite unstable due to the long bond length of the I-C bond?

[woelen]

Ryan, thanks for that synth you mention with red P, I2 and CH3OH. I am going to try that reaction on a small scale. I have all three chems. I did not know of that.

 

Woelen, wouldn't iodomethane be quite unstable due to the long bond length of the I-C bond?

Yes, it is quite unstable. That is why it is such a good methylating agent. It can easily split off a CH3-group.

[RyanJ]

Ryan, thanks for that synth you mention with red P, I2 and CH3OH. I am going to try that reaction on a small scale. I have all three chems. I did not know of that.

 

No problem, let me know if it works ok. The book suggests this as the best reaction too use even though it does warn the reaction is exothermic to some degree (but isn't more specific).

 

Yes, it is quite unstable. That is why it is such a good methylating agent. It can easily split off a CH3-group.

 

Interesting, thanks! Then fluorine will be the least powerful methylating agent.

[woelen]

Methylfluoride is quite inert, as many of the fluorocarbon compounds. This is what made the freons so popular. Their inertness makes them non-toxic. But unfortunately, at high altitude with lots of UV-light they cause catalytic decomposition of ozone, by means of a radical/recombination mechanism.

[RyanJ]

I guessed as much, after PTFE being a great example of the stability of alkylfluride stability (or rather polymers off).

 

Thanks for the information Woelen!