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PHILOU Zrealone
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Quote: Originally posted by Myeou  |
no no ... i mean seriously , i read a few synthesis method like acetylene through nitric acid , acetic anhydride and nitric acid .
But none of them comes logical . Can someone wright the mechanism of them. I mean that methods are really work ?
[Edited on 8-12-2012 by Myeou] |
Mechanisms are quite obscure because many things happens all together:
-Addition of HNO3 and elimination of H2O on double bonds
-Addition of NxOy
-Nitrite hydrolysis
-Nitro-nitrite rearrangements
-Nitrosation and isomerisation into oxime
-Oxydations of carbons and of oximes
-Decarboxylation of nitrocarboxylic acids
-Nitro-keton hydrolysis
-...
If you look at all those reactions individualy and understand fully the principles in action behind; then you might understand the all story and that
sometimes excess carbon is destroyed in the process and degraded.
[Edited on 10-12-2012 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
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| Quote: Originally posted by Myeou |
I dont get it . I mean how is it possible synthesis nitroform from isopropanol. Can anyone wirght the mechanism ?
Shouldn't iso-propyl nitrate form ? |
The chemistry appears to be similar to the haloform reaction.
It is actually quite problematic to nitrate isopropanol to isopropyl nitrate. Apparently the alpha hydrogen is more vulnerable to oxidation than other
alcohols. This subject has been discussed in detail in other places in this forum.
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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AndersHoveland
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| Quote: Originally posted by chemoleo | Well, this was put to the test.
Iodoform (a few spatula tips), made according to the method here, was dissolved in ether (25ml), which formed a pale yellow solution.
To this AgNO2 powder (yellow grey) was added, also a few spatural tips, keeping the solution on ice all the while. The AgNO2 didn't dissolve.
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The AgI product may have been forming a protective coating over the AgNO2 particles, preventing further reaction. With these types of reactions, often
both reactants have to be first dissolved before they can react together.
Even then, I would expect the yield to be quite low. While the nucleophilic substitution reaction of a haloalkane with silver nitrite mostly forms the
nitroalkane, a lesser portion of the nitrite ester is also formed. As should be self-evident statistically, the yields become progressively lower as
there are more halogens on the same molecule to be replaced by nitro groups. I remember reading somewhere that the yields of tertiary nitroalkanes
from their respective halogen-substituted reactants is only around 11%. You see, even if only one of the iodine atoms in iodoform becomes substituted
by a nitrite group (rather than nitro), it will open the molecule up to hydrolysis, and all you will get is formic acid.
Something else to mention: Nucleophilic substitution reactions on haloalkanes generally only work when the halogen atom is bromine or iodine. The rate
of reaction with chloroalkanes is generally negligible (the reaction takes 6+ months). (there are ways to speed this up, but they are not applicable
here)
| Quote: Originally posted by chemoleo |
When adding a couple of ml of this to H2O, the yellow colour remained in the etheric fraction  , which is unfortunate because the TNMe should really dissolve in H2O. No visible reaction of the etheric extract with 34% formaldehyde
either - but again part of the problem could be because the solutions don't mix.
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Trinitromethane is going to be more soluble in ether than water. Similar color concentration in the oil fraction layer can also be observed with
bromine.
Trinitromethane forms bright yellow nitroformate salts with bases.
| Quote: Originally posted by chemoleo |
I shall add some more AgNO2, to see what happens with it. Lateron I might try the same wtih NaNO2, and ethanol.
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Probably either AgNO2 or NaNO2 could be used. The silver salt is often preferrable for several reasons: Many silver salts have unusual solubility in
benzene (the Ag ion coordinates with the aromatic ring). The formation of AgI/AgBr/AgCl is favorable and helps drive the reaction. And the silver
halide byproduct is insoluble and can be easily filtered out.
If using NaNO2, a good solvent might be DMSO.
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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AndersHoveland
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Tetranitromethane has been obtained from iodopicrin I3CNO2 and silver nitrite AgNO2.
Hantzsh, Chemische Berichte, 39, p2478, (year 1906)
But this raises some questions. If trinitromethane instead of tetranitromethane is being produced, could this not form the explosive silver
nitroformate in the reaction? And would not tetranitromethane (which is a reactive nitrating agent itself) oxidize some of the nitrite to nitrate,
being reduced to trinitromethane?
[Edited on 14-12-2012 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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plante1999
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I tested Anders isopropanol and 99% nitric acid death wish, or should I say process. I was in the idea that heating 99% nitric acid and adding
isopropanol was a bad idea, so I added a drop of isopropanol in room temperature nitric acid, the reaction was very violent, making a cracking sound
and splashing mixture. It was evident the reaction mixture should not be heated, but well cooled. While swirling the flask and making the isopropanol
running on the side of the flask the reaction was much moderated, up to the point I got a runaway. I quickly improvised a water bath, and managed to
stop the runaway and add the remaining isopropanol. Because I love my limbs I preferred to lets the mixture set for about 10 hours at room temperature
instead of cranking the heat up for two hours.
Hopefully some yield will be obtained even with the runaway, otherwise the reaction will be re-tried with cooling. Altough extremely dangerous, the
process seams to be working at the point I am.
When the waiting will be done, an extraction with 1-3 dichloropropane wll be made, due to the lack of other chlorinated solvent. The extract will be
reacted with potassium hydroxide dissolved in methanol to precipitate the potassium nitroformate.
I never asked for this.
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plante1999
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The extraction was tried, it definitely did make some precipitate that was colored yellow, although it was highly contaminated with potassium nitrate,
the dried salt smoldered when lighted, but was definitely highly impure. The process show very high potential, but I need to improve the recovery of
the trinitromethane.
Any idea is welcomed.
I never asked for this.
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Azane
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TNM from DNM?
Sorry for barging in on a thread that hasn't been active for over a year, but does anybody think that it might be possible to nitrate dinitromethane
(or derivatives thereof) into trinitromethane? DNM is pretty easily obtained as one of the products of the reaction between nitric acid and
hexamethylenetetramine (the other products being water, ammonium nitrate, and RDX), and the dinitromethanide anion is has been investigated as a
component of imidazolium ionic liquids and experimental shock-insensitive explosives. The fact that the anion exists means that either DNM itself can
be deprotonated (doesn't sound unreasonable), or that derivatives of DNM (particularly halodinitromethanes, which could be obtained by the oxidation
of dinitromethane with the respective halogen) can be reduced (by alkali metals or alkali hydrides?) into halides and dinitromethanides.
It might be possible to nitrate the DNM anion with a nitronium salt or nitric acid. Nitration with a nitronium salt would be a simple Lewis acid-base
reaction, and therefore more straightforward, but I'd be worried about a runaway reaction and the decomposition of the formed TNM. Nitration with
nitric acid would proceed via a condensation reaction, and might, therefore, be less favorable, as condensation reactions often require heating and
additional acid (as catalyst) to occur, again risking the decomposition of the product.
Halodinitromethanes offer an alternative route to those involving the nitration of the anion. If they're stable (I've seen reference to
bromodinitromethane) they could be reacted with a nitrite salt to displace the halide, rendering TNM and a halide salt.
I still need to do more research on these ideas, but does any of that sound good?
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PHILOU Zrealone
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DNM is quite unstable because part of the -NO2 turns into -ONO (nitro-nitrite rearrangement).
It is sensitive to base media and to acidic media.
This effect is also present in TNM but to a lesser extend and into TeNM in an even lower level.
The best (and safer) way to nitroform is probably via TeNM and reduction.
In the above stated reactions:
1°)
iodoform/AgNO2 may work but one needs a good solvent of both reactants (maybe DMF or DMSO; an alternative may be aceton/propanon, but with lower
yields.)
The main problem with AgNO2-haloalcane way is that each NO2 may introduce into the molecule as 60% nitro and 40% nitrite.
If one nitrite is included, the molecule will destroy itself via hydrolysis...
First step:
CHI3 + AgNO2 --> CHI2-NO2 (60%) + CHI2-ONO (40%) + AgI (s)
Note that AgI is a pale yellow precipitate turning yellower/ darker upon light exposure...because metallic Ag forms and I2 is set free...in most
organic solvents I2 will turn yellow, orange, brown or black depending on concentration in polar solvants (it will be violet in some other apolar
solvents).
CHI2-ONO will likely be destroyed
Second step:
CHI2-NO2 (activated halide) + AgNO2 --> CHI(NO2)2 (60%) + CHI(NO2)(ONO) (40%) + AgI (s)
Again the nitrite substitued part will be lost in fumes.
Third step:
CHI(NO2)2 + AgNO2 --> CH(NO2)3 (60%) + CH(NO2)2(ONO) (40%) + AgI (s)
Again the nitrite substitued part will be lost in fumes.
The overal yield can only be at best 60% x 60% x 60% = 21,6%
Starting from chloropicrin and AgNO2 one may go slighly to a better yield because one initial nitro group is already present and thus only two
substitutions are critical (last nitro group can be set as a nitrite without much harm in TeNM because in equilibrium)...maximum yield 36% (60% x
60%).
C(NO2)4 <==--> C(NO2)3(ONO)
2°)
The processus may use KNO2 or for better solubility NaNO2 or even better LiNO2 in an appropriate solvent instead of AgNO2, but the yield of nitro
substitution is lower than 60% and sometimes it goes almost exclusively to nitrite substitution.
3°)
The nitric acid/isopropanol way may be replaced by HNO3/ propanone (aceton)...the first oxydation step of isopropanol being propanone and thus much of
the exothermicity of the reaction is already spared.
Beware that even so Aceton/Nitric acid makes very fast a runnaway after a short induction period; the mix very fast heats up, boils up and free NxOy
nitrous fumes...very long and good cooling condenser is needed!
Such mixes must be in great excess of HNO3 in a way to ensure polynitration but also to temper the heat AND BE FAR FROM PERFECT OB MIXES which are
detonable by heat and shock...such molecular mixes of oxydiser and fuel with conc HNO3 are as sensitive and powerful as NG!
Aceton probably react by a first addition of HNO3 via its enol form...leading to nitroaceton.
CH3-CO-CH3 <==--> CH3-C(OH)=CH2
CH3-C(OH)=CH2 + HO-NO2 --> CH3-C(OH)2-CH2-NO2
CH3-C(OH)2-CH2-NO2 --> CH3-CO-CH2-NO2 + H2O
The following steps must involve nitrosation of the nitromethyl moeity by NxOy and oxydation to polynitro compounds...finally splitting of the acetyl
part and nitroform liberation.
4°)
The reaction of MNM, DNM with halogens usually ends up in a mix of halonitrocarbons that are dangerous because of their toxicity (related to
chloropicrin, and the halogen is very labile because activated by the nitro group(s)...those are potent lachrymator and war gases very avid to react
with any living moist membrane (lungs, mouth, eyes, nostrils).
MNM forms chloronitromethane, dichloronitromethane and chloropicrin.
DNM will form chlorodinitromethane and dichlorodinitromethane.
The mix is difficult to separate...for the mononitro compounds, this can be done via distillation, but for the dinitro compounds distillation is
unadvisable owing to the very high risk of detonation...keeping in mind the war gas nature of the compound in the event of a glasware break or
explosion....
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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