UnintentionalChaos
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Nitromethane (revisited)
There was an old thread on preparing nitroalkanes, but it seemed to be mostly focused on nitroethane and could do with a summarization.
http://www.sciencemadness.org/talk/viewthread.php?tid=2995&a...
Anyway, for a college project (a club actually) we are looking into using a nitromethane/methanol fueled engine to generate power. If a nitromethane
synthesis can be carried out, the engine will probably be implemented into the design. The only problem is that we'd HAVE to synth the nitromethane
ourselves to fit the terms of the project. I have access to lab equipment and many chemicals if they are needed as well as a group with a lot of lab
experience. From the old thread, a few of the synths are adapted here.
1: The reaction of a methyl halide with an alkali nitrite in DMF
2MeOH + 2NaHSO4 -> Me2SO4 (yes I recognize the toxicity) + Na2SO4 (formed both anhydrous and as decahydrate at low temperatures)
Me2SO4 + 2NaI -> 2MeI + Na2SO4 (does this reaction occur? or can it only become NaMeSO4?)
MeI + NaNO2 -(DMF)-> MeNO2 + NaI
2: Alternately dry distillation or reaction in water of:
NaMeSO4 + NaNO2 -(K2CO3 at 2.5% the molar quantity of nitrite)-> Na2SO4 + MeNO2
3:Good old chloroacetic acid and NaNo2 -> nitroacetic acid + NaCl -> MeNO2 + CO2 + NaCl
Would it be possible to produce the chloroacetic acid oneself? You could hydrolyze trichloroethylene with a H2SO4 catalyst, but does anyone have an
idea as to how to seperate the HCl from the Chloroacetic acid?
4: The Davster suggested that diazotizing glycine, followed by a reaction with an alkali iodide would provide iodoacetic acid which could react with
an alkali nitrite as in the above procedure. Wouldn't the side product of the alkali iodide reaction be an alkali diazide?  Something chemically between an alkali nitride and an alkali azide can't possibly
be stable or safe (even less safe than the MeNO2 and probably extremely reactive with water). Or am I wrong here?
Has anyone here actually carried out a successful synthesis of nitromethane other than from the chloroacetate route? Thank you in advance.
[Edited on 1-19-07 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Dr.3vil
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Dragster fuel
I cant comment on the synth, however from an engineering standpoint, essentially you'll be generating electricity with what amounts to dragster fuel.
This presents its own issues relating to ware on the engine and the possibility of a failure (ever see a dragster engine explode?)
Could you provide more details about the project? If this is an alternative energy project, the nitro would seem to be overkill??? If the project
relates more toward lab technique, have you considered Biodiesel? You could compare MeOH to diesel both of which can be obtained from organic
feedstock and involve different synthetic methods.
- 3vil
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guy
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http://designer-drug.com/pte/12.162.180.114/dcd/chemistry/ni...
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garage chemist
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Why do you want to make methyl iodide from the dimethyl sulfate? I know that it works (I have a synthesis procedure), but it is not necessary at all!
If you have DMS, you can just react it with your NaNO2 in e.g. DMF or maybe DMSO to get your product. It is an alkylating agent as well, and MeI
actually reacts much slower than it.
Methyl iodide can also be made from KI, H3PO4 and methanol. I would think that this is also worth considering, especially as the chemicals used are
quite benign (though the product is not).
Of course you can also do the classic prep for MeI, which involves reacting iodine and red phosphorus with methanol. PI3 is formed as the
intermediate. This reaction gives much better yields than KI/H3PO4. It depends if you are given access to red P for the project.
Chloroacetic acid is made by chlorination of glacial acetic acid with chlorine in sunlight, red P or sulfur being used.
The yield of nitromethane from chloroacetic acid is low, but it is by far the easiest method.
I think you should ask if you can use chloroacetic acid and NaNO2 as the starting point. It will be the least time- consuming.
You will have to purify your nitromethane very well, especially if you want to make it from methyl iodide. There must be absolutely no traces of MeI
left, otherwise the motor will be destroyed. Fractional distillation over an efficient column is the minimum requirement.
[Edited on 20-1-2007 by garage chemist]
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UnintentionalChaos
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Its actually a group called the Chem-E (for chemical engineer) car and they ahve regional and national competitions. We went to nationals last
semester with a massive Cu/Zn CuSO4 electrolyte battery running an electric motor and a NaOH/CuSO4 titration to signal the cut in power. The idea is
that you are made to go a certain distance with a certain load (0-100g water, which doesn't mean anything when the car weighed 20kg), but you aren't
told how far, so adjustments must be made to quantities/molarity of solutions used at the last moment. We probably would have won, except our
electronic controls linking the chemical components were overambitiously complex and a small failure days before nationals was unable to be located
and repaired in time. We made heavy modifications at the last moment, but it did no good.
Anyway, this semester, they don't mind going a completely different direction and using a motor. The guy who suggested(and donated for our use in the
project) the motor is quite experienced with it and has used it for years without incident. The senior year mechanical and electrical engineers on the
team think that they can handle it, but I'm somewhat in charge of research on making the fuel because I can spit out quantities of info that will
leave the senior chem engineer confused....especially my knowledge of household products and their components (since we are on a fairly tight budget)
Our second course of attack, should the engine fail is a dry cell battery of aluminum and copper foils with a membrane immersed in an electrolyte. We
are still doing tests, but it looks promising.
We have months before competition, so plenty of time to make our own chemicals from basic materials. We may end up doing the chloroacetate for the
sole reason that photochloronation is probably not a synth the senior chem-e has done and it would be quite fascinating
With regards to the biodiesel, there was a design project last year where a functioning continuous biodiesel reactor was made. It could produce
several quarts a day and ran constantly. It is also not a terribly original idea, since several of our competitors cars have used it before. 
[Edited on 1-20-07 by UnintentionalChaos]
Even more editing: What yield of chloroacetic acid is obtained by photochlorination? Can it be pushed to completion by an excess of chlorine and long
reaction time? If not, how can the chlorinated acid be seperated from the unreacted acid?
In what medium (or lack therof) is the chloroacetic acid reacted with the nitrite? I can find references to the reaction occuring but have not found a
detailed synth explaining the procedure.
[Edited on 1-20-07 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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The_Davster
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Excess chlorine favours the dichloro and trichloroacids. I am pretty sure the reaction has good yields, once a certain mass increase is observed, you
are done! Stop!
The medium for the nitrite method with chloroacetic is carried out in water, check orgsyn or the designer drugs link above.
Anyone know if the glycine idea would work? I was just hypothesizing before.
Moved to organic
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