GluckMaker
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Dimethyl sulphate recycling
Hello,
I am going to get 2 liters of DMS from a surplus lab for free, but I don't know what to do with it due to its toxicity. I want to make something less
dangerous, but still useful from it in 1-2 reactions with simple workup (to avoid contact). What can I prepare? My current targets are methyl iodide,
nitromethane and methanol (it is cheap but prohibited in my country).
My plan is:
1) conduct the methyl iodide preparation presented here: http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV2... , but get an excess DMS to consume all iodide (it is expensive). After MeI
distillation, add a strong base (KOH) to hydrolyze resulting MeKSO4 and any residual DMS. Distill out methanol.
2) make nitromethane as here: http://www.sciencemadness.org/talk/viewthread.php?tid=13633&... (second part). It is a surprise for me that DMS does not hydrolyze in contact with
some water solution. Distill out MeNO2. Add some KOH solution to take care of unreacted DMS.
Any other ideas?
I am going to work outdoor, with a gas mask and hard latex gloves. Is it an enough protection? Does an ordinary (activated carbon) gas mask protect
from it? Are the products contaminated with DMS? I know it has a big vapor pressure, which means, I think, it should pass through distillation in some
small quantities. Wash with some aq. NaOH?
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psychronizer
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methanol is prohibited in your country? where are you? maybe u live in one of those lands that do nasty things to alcoholic drinks,topping them up
with methanol! or (slightly less evil) ethylene glycol.....I'm just joking.but still, back to why I am here. forget the goddamm methanol, thats a
blasphemous waste of DMS....let your fingers guide you, on your fingering way thru pages of reactions to decide on what to do with it...but for god's
sakes DONT get it on you or breath in the hot fumes while you're in the middle of methylation....that stuff will send you rocketing to the dead
house....I think your synth ideas are ok...but please bear in mid what I have said.....dont get it on or in you....
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S.C. Wack
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It's the last thing I'd do with it, but...methylamine HCl?
Preparation of Methylamine from Ammonia and Methyl Sulfate. JAMES BURMANN (Bull. Soc. chim., 1906, [iii], 35, 801-803). - Commercial methyl sulfate is
added in small portions at a time to excess of a 10% aqueous solution of ammonia cooled to -5C. The product is then added to excess of a 30% aqueous
solution of NaOH and the mixture distilled, the issuing gas being passed into 20% hydrochloric acid. On evaporating, the ammonium chloride separates
first and the methylamine hydrochloride ultimately obtained is purified by recrystallisation from boiling absolute alcohol. The yield is about 35% of
the theoretical.
JCS 90, 933 (1906)
I imagine methanol can be recovered from the distillate from the NaOH. The original article would have to be seen to clarify whether theoretical
refers to one or both methyls...I'd think one even in 1906 but you never know...
[Edited on 23-3-2013 by S.C. Wack]
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SteveZissou
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This is an odd predicament, indeed. While highly useful I don't blame you for having hesitations working with the stuff. You could make yourself some
nice o-methylated aromatic rings (what I'd do) or if you're wanting to convert it into a different reagent the slightly less toxic methyl iodide
sounds like a good idea. Methyl bromide, IIRC, has the same kind of reactivity and it's cheaper to produce if you wanna go that route.
If you don't have a proper working fume hood then forget it, just hydrolyze the stuff with alkali and use the sulfuric acid and methanol for other,
non-carcinogenic, activities.
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