Hey guys, since there are a few people on here that I haven't seen before, perhaps this will get answered.  I was wondering if anyone here knows any reliable sources of methylating agents.  This could include (but not limited to) dimethyl sulfate, trimethyl phosphate or dimethyl carbonate.  The last two would be prefered as they're no where near as toxic as dimethyl sulfate.  I have searched quite hard and have been unable to come upon any.  I know I could make dimethyl sulfate, but I'd rather not, as I'm more interested in dimethyl carbonate or trimethyl phosphate.

A couple things that may be of intrest the first you would need someone that can pull up the springer link.

Some investigations of the mechanism of the so-called “methylation” reactions used in mucosubstance histochemistry
http://www.springerlink.com/content/n5476l37712u7101/


Boron methylating reagent.
http://www.jlr.org/cgi/reprint/12/6/773.pdf


I look for more when I get time later

It's pretty much MeOH + I2 as I understand it.

No, HI + MeOH

DMI is a decent reagent for methylation.

MeI** not DMI (just to avoid any confusion)
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Boron trihalides are strong lewis acids, so I wonder if the more easily prepared aluminum chloride could be used in place?

Anyone have ideas for making Trimethyl Phosphate? This one is probably the safest and most useful methylating agent out there, if we could figure out how to make this, life would be good.

DMC I don't believe is of much use, though is easily produced from methanol and phosgene. Phosgene could be made a multiple of ways, but I'd probably go with CO and Cl2 over activated carbon.

Methyl Nitrate, as Enkidu posted is tempting since it is so easy to make, to bad it is pretty sensitive.

Hmmm, I'm curious if methyl nitrate is strong enough for producing methoxy groups.  I may just have to try this (mescaline).

Well MeI can be made with Na/K iodide and H3PO4, and I believe even H2SO4 if the concentration is kept low enough, with methanol, similar to the ethyl bromide preparation.  I also think there was a way to prepare HI in situ from elemental Iodine, using sulfur and aluminum IIRC it was on science madness.  RP and iodine obviously generate HI, but RP is a problem.  Sulfur often makes a decent sub for phosphorus, however in this case it doesn't react freely, which is where I believe the aluminum comes in, or something to that effect.  Maybe it was aluminum and Iodine making AlI3 (AlI3 + 3H2O ----> 3HI + Al(OH)3).  I can't remember if that works with methanol in situ though. 

Possibly.  Alcohol + HCl + lewis acid will yeild the appropriate alkyl chloride.  A lewis acid commonly employed for this is ZnCl2, so it might be worth a shot, by adding a couple grams of ZnCl2 to the reaction.  Give it a shot, if you want.

Alright guys, after some reading around, I believe methyl tosylate is quite in reach.  It wont be an easy procedure, however methyl tosylate is quite powerful, yet very safe (as compared to MeI and DMS).  Below is the preparation of butyll tosylate from tosyl chloride and butanol:
http://orgsynth.org/orgsyn/prep.asp?prep=cv1p0145
obvious substitution of methanol for the butanol does yeild the correct product:
http://www.sciencemadness.org/talk/viewthread.php?tid=11004#pid133307

As for tosyl chloride, it can be prepared from quite OTC materials, if you substitute aniline for aminobenzotriflouride. 
(tolune ---> nitrotoluene ----> aniline)
SO2 can be generated from sodium dithionite, which is 'RUST RAZE', a rust remover available in grocery stores.  Just add HCl.  It's not the most favorable route, but its a route regardless, and it's a methylating agent that works quite well and is no where near as toxic.

Um, I'd just buy the tosyl chloride. What substrate do you plan on methylating? Phenol? Amine? Carboxylic acid?

A LOT of SO2 gas can be generated from only heating a little mercury metal in a bit of con. H2SO4 ~200C.

...and I mean a lot.

Does it work as a catalyst somehow? sounds interesting.
 Burning sulfur is another option but sucks regardless how available sulfur is. I like the rust remover method the best. I've done it, and it works great and makes nice clean SO2.

And to Douchermann...

(tolune ---> nitrotoluene ----> aniline)

You mean Methylaniline, right?

Um, I'd just buy the tosyl chloride. What substrate do you plan on methylating? Phenol? Amine? Carboxylic acid?

I think most people are interested in phenols, making 3,4,5-trimethocy and 2,5-dimethoxy compounds.

Either way, it is important to find a way to make a decent methylating agent.

It does not create it at an extream rate but The hydrolysis of Sodium metabisulfite with H2O generates SO2 pretty well. It dont do it extreamly fast(It may with a little heat Iv never tryed) but its a clean gas output.

You could always add sulfuric acid to it as well to produce some decently clean SO2.

Know much more about dimethyl oxalate as a methylating agent? there is some info on it here: http://www.sciencemadness.org/talk/viewthread.php?tid=11580

I had an idea.. that probably won't work but lets hope that it does!

Na2S2O7 is produced by heating/dehydrating NaHSO4. Na2S2O7 will reform back into NaHSO4 with the addition of water.
What if you were to add Na2S2O7 to MeOH instead though? My guess is that it would form NaHSO4, and NaCH3SO4. This might have to be separated, but I don't think it would be that hard to do with solubility, in say methanol. I think heating them together would produce CH3HSO4 and Na2SO4 so that would be something to worry about.

Na2S2O7 + HOH = 2 NaHSO4
Na2S2O7 + CH3OH = NaHSO4 + NaCH3SO4

Sodium methyl sulfate may not work as the classical methylating agents do, but I don't see why it would not work to methylate phenols.

If one were to have sodium phenolate and react that with sodium methyl sulfate, wouldn't it yield Na2SO4 and methoxybenzene? 

PhONa + NaMeSO4 = PhOMe + Na2SO4.

I'd love it this were true, but I'd like to see why this wouldn't work. Any input?
While you think about this, I'll be fantasizing about an OTC mescaline synthesis.