Author Topic: CH3-C6H5SO2*CH3O - an OTC methylating agent?  (Read 6126 times)

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Antoncho

  • Guest
CH3-C6H5SO2*CH3O - an OTC methylating agent?
« on: July 16, 2001, 07:27:00 PM »
This is from an old Russian chemistry textbook:

Alkylation with alkyl esters of  arylsulfonic acids:

C6H5ONa + ArSO2*CH3O ----> C6H5OCH3 + ArSO2*Ona

The rxn is carried out just like with dimethylsulfate, by energetic shaking the mixtr of the reagents in aq. alkali, followed by heating. It also goes to completion in alcoholic soln or by heating the dry phenolate with addition of a neutral solvent where necessary (benzene, abs. acetone)

It is noted there that these esters are by far not as poisonous as dimethylsulfate is, which is surely nice, I must say. However, they still are “partially toxic” and tend to cause exema (I don’t know how it spells, yes…)

The esters themselves (mainly p-toluylsulfonic methyl ester), the book states, can be prepared from mixing toluylsulfochloride w/methanol, followed by aq. NaOH with cooling below 25 C. Its mp is 28 C, mp of ethylester 32-33 C.

The book also says that toluylsulfochloride is easily available as a by-product of sugar industry. But for someone i have known and loved, PCl5 or POCl3 to make it are out of question because of their being grossly expensive (and so is dimethylsulfate).

So he wonders, if it is possible to make them in a conventional manner that acid esters are made – that is, by simply boiling p-toluylsulfonic acid w/methanol with some catalytic H2SO4?

 P- toluylsulfonic acid can be easily made by boiling toluene w/H2SO4 conc.

Humbly awaiting your replies,

Antoncho

P.S. This information wasn’t exactly found by me, it comes from a Russian small analog of the Hive, named HyperLab (www.hyperlab.org or

http://www.voy.com/12987

). This place – the Hive, I mean – has always been the main source of data input for this petite clandestine community  :) , here’s one of the few occasions when the reciprocal process can take place  :)   :)   :)

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #1 on: July 16, 2001, 07:42:00 PM »
If the esterification is possible that way (which I think it is), the catalytic H2SO4 is definitely not needed, the toluenesulfonic acid is good enough as catalyst.

If I take a look at the board, it is almost exclusively in russian, which makes it impossible for the rest of us to understand (afaik, you are the only russian on this board), so could you please copy over the most interesting syntheses to this board? Also, is there anything revolutionary to be found at

http://dissociative.h1.ru/

?

I would also like to say that you are invaluable for us here at the Hive, as you can translate all those interesting articles and patents we find.

obituary

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #2 on: July 16, 2001, 09:33:00 PM »
in terms of methylating something, would this apply to mono-methylation of amphet?  methylation of OH on ring to methoxy? what about aliphatic OH's?

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #3 on: July 16, 2001, 09:46:00 PM »
It would apply to phenols and possibly aliphatic alcohols. Methylating amphetamine with it would produce a mixture of mono- and dimethylated amphetamine.


https://www.rhodium.ws


Osmium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #4 on: July 17, 2001, 12:07:00 AM »
Another good methylating agent is trimethlyphosphate, and I heard rumours that dimethylcarbonate works too.

Antoncho

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #5 on: July 17, 2001, 10:55:00 AM »

If the esterification is possible that way (which I think it is), the catalytic H2SO4 is definitely not needed, the toluenesulfonic acid is good enough as catalyst.


Thank you very much for your comments, Rhodium! I guess i'll try this rxn over the weekend and post the results, however i have nothing methylatable at hand to test it upon. Which brings me to ask you, guys, how would one go about separating the ester from the unreacted acid? I'd imagine that methyl toluylsulfonate is pretty soluble in water, isn't it?
Can you just saturate the mixtr with aq. bicarbonate and extract the ester w/a non-polar? I'm sorry to ask such basic questions but i don't really have much practical expeience w/lab chemistry... :)  :)


If I take a look at the board, it is almost exclusively in russian...


yes, it is... :)


afaik, you are the only russian on this board ...


As far as i know there used to be another Russian guy here - that one was a real chemist! - named Assholium. The one that claimed to have made the 4-rhodano-2,5-methoxy thing (which i have no doubt he indeed had). He said there were still many syntheses by him on your page :):) But we also lost contact w/him a long while ago. You might also be familiar we someone by nickname Jerry (aka Akim D. aka Apologet) who was the founder of our Russian project; as far as i know, he had a few acquaitances both here & in Lycaeum.

By the way, what does 'afaik' mean? :)


so could you please copy over the most interesting syntheses to this board? Also, is there anything revolutionary to be found at

http://dissociative.h1.ru/

?


Yes, i'm working on it... Not like there's an awful lot of new information, but a couple of synths will surely surprize you...

http://dissociative.h1.ru/

  deals mainly w/syntheses of PCP and its analogues - it used to be very popular in European Russia - , i believe that most methods on the site are not covered here, but i didn't get into much detail when looking through them, being uninterested.



I would also like to say that you are invaluable for us here at the Hive...


Oh my fucken Jesus... no comments, though  :)  :)  :) . Always welcome.

Antoncho


P.S. Can anyone, PLEASE, take a look at my write-up about Al+NaOH+CH3OH in Acquisition forum? Really need some clarification on the subject.




Antoncho

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #6 on: July 17, 2001, 10:58:00 AM »
I noticed the change in the title... Dear Sirs, let me gratefully tell you that I feel truly hohored...

Antoncho

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #7 on: July 17, 2001, 01:15:00 PM »
Synthetic suggestion:

Boil 100g of p-toluenesulfonic acid with 1000ml methanol for 12h, evaporate most of the methanol under vacuum, wash with 50-75ml portions of concentrated aqueous bicarbonate until neutral (backwash the bicarbonate extracts with 2x50ml non-polar), add an equal amount of water and separate the organic layer. Extract the aqueous phase with 3x50ml non-polar solvent. Combine all the non-polar extracts and remove the solvent under vacuum, and if desired (I think it is needed) vacuum distill the methyl p-toluensulfonate.

Afaik stands for "as far as I know"...  :)  I would really like that assholium guy back here, he was a really great chemist. Unfortunately, his rhodanation reaction does not work as advertised. Only anilines and free phenols react with thiocyanogen without a lewis acid catalyst, and the literature is VERY scarce on the subject.


https://www.rhodium.ws


Osmium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #8 on: July 17, 2001, 03:10:00 PM »
Didn't he use Br2/thiocyanate? Or will that mixture form the dimer of thiocyanate?

Rhodium

  • Guest
Thiocyanation attempts of 1,4-dimetoxybenzene
« Reply #9 on: July 17, 2001, 04:03:00 PM »
Yes, he did. The literature does not clearly answer if 2 KSCN + Br2 produces KBr + BrSCN or 2 KBr + (SCN)2, so the active thiocyanation agent may either be BrSCN or (SCN)2 in his case. Either way, a test run on 1,4-dimetoxybenzene yielded only starting material and an orange thiocyanate polymer. Pb(SCN)2 + Br2 (which gives PbBr2 + (SCN)2) in solution also gave nothing but starting material, but less polymer was formed. A literature search confirmed that thiocyanation of phenol ethers requires a lewis acid catalyst, preferably Al(SCN)3 (but this has not been tested).

Antoncho

  • Guest
p-Toluenesulfonic acid (Tosic acid) synthesis
« Reply #10 on: July 28, 2001, 08:42:00 PM »
Well i'm afraid this rxn doesn't work at all  :(  :(  :(

I still post the story of what SWIM did so that you guys (Rhodium? ;) ) see if SWIM  didn't fuck smth up.

p-Toluenesulfonic (tosic) acid (method taken from

http://zaratustra.narod.ru

)

In a 500 RBF equipped w/a reflux condenser SWIM  placed 76 ml toluene and 45 ml conc. H2SO4. They didn't mix, duhh. This was immersed in an oil bath which was maintained at ~125 C during the rxn. The toluene never really started to boil, so SWIM just shook it occasionaly for an hour (don't take the  condenser off! Toluene starts to boil as you shake it) - maybe 12 shakings were needed. At this point most toluene was consumed (26 ml left) and the bottom layer was brownish yellow. To this 170 ml of water and 1.7 g activated charcoal were added and some of the mxtr was distilled off until the distillate stopped smelling like toluene. The charcoal was filtered off at this point and the mxtr became clear and slightly green. It was further concentrated to 140 ml volume.
SWIM  then put it in the freezer overnight and the next morning a little amt of crystals was observed at the bottom. The flask was immersed in an ice bath and saturated w/unhydrous HCl at 5-10 C. (Jesus, you should've seen SWIM's kitchen lab! All the equipment w/the xception of the (the only:) condenser is self-made  ;D  - you ever seen a self-made pressure-equalized dropping funnel charged w/conc. H2SO4? SWIM's consists of 2 flasks, 2 rubber stoppers, 4 glass pipes and a polyethylene crane that - get it - leaks.  It is a very fortunate circumstance though, cause when the bubbler pipe gets plugged up, you can see that sulfuric acid starts to drop out of the crane's handle faster... And so you can prevent the funnel from blowing up... SWIM  must confess SWIM missed that particular moment once  ::)  - fortunately, with no disastrous consequences) Gassing surely has been the shittiest part of the experience for SWIM and, yes, it took a long while. When HCl was no longer sufficiently absorbed (i.e., it started to appear at the flask's mouth) the mixture was thick w/white crystals and intensely yellowish-green. The crystals were filtered w/sucction on a Buchner funnel, then washed w/a little ice-cold HCl, which removed the remnants of green from them and sucked as dry as possible. They were put in an exicator (guess what it looks like:) over conc. H2SO4 and solid NaOH. And there they still are - they should be dried for several days. SWIM didn't weigh them yet but the yield was decent.

But SWIM , being young and impatient, decided that since water is formed in the rxn anyway and HCl would very soon go away as CH3Cl (as indeed happened) he'd just take some of his wet tosic acid and proceed w/it. So he weighed out 22 g of it (2 g added for moisture) of it, dissolved in 100 ml CH3OH and dryed the soln. w/freshly pulverized Na2SO4 - an large excess was added and left in the flask to absorb the moisture that would supposedly be formed further. This was refluxed for 18 hours. The mixtr turned yellow and unclear. It was neutralized w/saturated aq. bicarbonate (~130 ml) (CO2 evolution was observed) and xtracted w/ 2x70 ml ethyl acetate, which removed all yellow color to the org. layer. The organic xtracts were separated and dryed w/Na2SO4.
Now SWIM doesn't have a vacuum so he just decided to boil the solv. off at ordinary pressure (ethylacetate bp 77 C, methyl tosylate bp 140 at 5mm) (bath set at 100 C), and when he did that all that was left in the flask was ~0.5 ml of dark brown gunk. Now, SWIM thought that maybe since they're both esters they might form an azeotrope or smth (SWIM doesn't know shit in chemistry;) and tried to evaporate the ethyl acetate from the distillate w/a hair dryer (a vacuum cleaner attached to the system as the fume hood :)  :)  :) ) - and that produced nothing else but 3 ml water (obviously SWIM didn't dry it well enough  ::) ) with some TINY oily drops at the bottom.

Well, ladies and gentlemen, looks like this approach doesn't work.

FUCK!!!

Well, maybe that methyl tosylate is so volatile that SWIM evap'd it all away but i highly doubt that :)

Still tosic acid is a useful reagent - it can be used in isomerizing THC. Also SWIM plans to try it as a TFA substitute in Duff formylation of dimethoxybenzene - that'd be really cool! If it worked...... SWIM is starting to get pessimistic - too bad for him! :)

BTW, can anyone w/an access to the library look up its pKa? I shall be REALLY grateful as i can't find it on the Web.

Antoncho

terbium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #11 on: July 29, 2001, 03:44:00 AM »
Be carefull in that all methylating agents - dimethylsulfate, methyl iodide, methyl bromide and probably even methyl toluenesulfonate are toxic and possible carcinogens.

Anyone know the chemical name of the methylating agent sometimes referred to as "Magic Methyl"?

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #12 on: July 29, 2001, 05:37:00 AM »
Methyl fluorosulfonate.



https://www.rhodium.ws


obituary

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #13 on: July 29, 2001, 07:02:00 PM »
is the flourine what causes that Me to come off so easily?

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #14 on: July 29, 2001, 07:28:00 PM »
Yes, as the fluorine is so electron-withdrawing, it stabilizes the SO3F- anion which forms when the methyl group comes off to such a degree that the compound will methylate just about anything.

obituary

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #15 on: July 29, 2001, 09:22:00 PM »
what kind of availability and cost is this compound?

Rhodium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #16 on: July 29, 2001, 09:29:00 PM »
The first hit on google for the compound is selling it for about $150 for 5g. I'd say that it is expensive  ;)

https://www.rhodium.ws


terbium

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #17 on: July 29, 2001, 10:04:00 PM »

$150 for 5g



Probably mostly handling charge. I seem to remember hearing a story of someone dying after spilling just a drop on the sleeve of his labcoat.


Chromic

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #18 on: January 24, 2002, 11:43:00 PM »
Is there any other route to separating the p-ToS? The gassing is something I'd really like to avoid.

Antoncho

  • Guest
Re: CH3-C6H5SO2*CH3O - an OTC methylating agent?
« Reply #19 on: January 25, 2002, 03:22:00 AM »
Yes, with conc. HCl - but the yields drop sharply in this case (the article says).

Antoncho