a123x
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Methylation with MeNO3
Seeing as methyl nitrate is somewhat easier to prepare compared to MeI and DMS, I was considering attempting to use MeNO3 as a methylating agent in a
Williamson Ether Synthesis involving some phenols. Has anyone ever used MeNO3 for such purposes? Does anyone know of a reason why it wouldn't work? I
can't really find any references to it being used, but plan to try anyway some time in the near future(I have to prepare some MeNO3 and purify some
other chems before I can try it) unless anyone knows that it won't work.
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SecretSquirrel
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Methyl nitrate is too toxic and dangerous/explosive to use for such purposes. But if you must use dangerous chemicals, use dimethyl sulfate insted.
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The_Davster
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'Don't use this chemical, its explosive, use the nasty carcinogen'
Assuming it can be used for methylations, it just comes down to which you would rather work with, an explosive(since its a methylation agent its
probably carcinogenic as well, but perhaps not as much?).
I guess it comes down to which you would rater use and are more comfortable with; an explosive or a carcinogen, personal choice really in my opinion.
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garage chemist
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It would be interesting to see if it works, I think it is because of the explosivity why this compound is not used in literature.
Go try it out if you are comfortable with it.
What do you want to methylate? I've done phenol to anisol using DMS, it works great, just reflux the solution for an hour afterwards to destroy excess
DMS (reaction of DMS with water is rapid at 100°C). The phenol is employed as a 10% aqueous solution of the phenolate.
Look here for a documentation of it: http://www.versuchschemie.de/topic,6037,-Anisol+%28Methylphe...
DMS isn't really that bad, a fume hood, safety goggles and gloves are the only protection you need. The boiling point is about 188°C, so it generates
very little vapor, which reduces the danger.
[Edited on 26-6-2006 by garage chemist]
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PainKilla
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There are references to this being used, though I have only seen reports of good yields on phenols, with few tests on other subtrates... No yields are
mentioned here (assuming they are decent though...):
82g eugenol (.5mol) and 30g (.54mol) KOH in 200ml methanol is stirred in a 1L RBF, at room temperature. 48g (.5mol) of crude 85% MeONO2 in 60ml
methanol is slowly added in portions over 2 hours. There is practically no sign of reaction, (ie precipitate). Heating this mixture carefully on a
water bath (be careful, nothing above 150C!!) gives a lot of precipitate after 30 minutes. Continue heating for another hour. The red liquid is
decanted, and the precipitate is washed twice with methanol. The reaction mixture can be evaporated carefully on a water bath.
Hopefully, someone has tried on other substrates with good results... (it was used industrially from what I understand, but it is a bit dangerous....)
If it does work, I think many would rather work with an explosive for 5 seconds, (ie make it and neutralize and transfer to a methanol solution) than
try to get and work with DMS. Also, it is important to keep in mind how OTC this is, there is nothing difficult about procuring MeNO3, while the same
cannot be said of any other methylating agent...
[Edited on 26-6-2006 by PainKilla]
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