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LD 50
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Preparation of nitroethane
I ran across this nitroethane synthesis that seems really straightforward and relatively simple.
Here is a basic rundown of the procedure.
In a 2000ml round bottom
500ml dimethylformamide
30g sodium nitrite
This is stirred vigorously for 10min to ensure a thorough mix, then immersed in a cold water bath. With vigorous stirring, 27g ethyl bromide is added
at such a rate that the temperature of the reaction does not exceed 25C. After the addition is complete, the reaction mixture is stirred for 6 hours
at a temperature below 30C. After 6 hours, the reaction mixture is poured into a large beaker and 1250ml of ice cold dH2O is added.
Extract with 90ml diethyl ether (x5)
Combine ether extracts
Wash with 75ml ice cold water (x2)
Dry ether extract by adding 15g MgSO4, stir for 10min.
Filter out MgSO4
Distill off ether @ 40C
Distill off nitroethane @ 115C
Store nitroethane in an amber bottle in a cool, dry place.
This seems easy, but the original writeup is vague. It gives no yields or purity. How would one go about scaling this up to, say, double this
volume? Is it as simple as doubling the measurements? How high is the risk of exploding oneself if one were to attempt this synth?
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LD 50
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Rather not link to the source, as it from a book that would be of interest to persons of ill repute.
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LD 50
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Thanks solo, I saw your posts.
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Chemosynthesis
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This didn't fit in any of the nitroethanr threads already on site? This looks almost identical to a procedure posted on one of the most famous sites
of ill repute, where yields are posted.
No offense, but this is pretty suspicious; you are asking for glassware, about Chinese chemical vendors, and now your first chemistry post is about
scaling up precursor synthesis? It doesn't help that your name is very toxicologically/safety pharmacologically oriented, yet you don't want to cite
your sources.... If the book is useful, just think how useful your post/replies would be for a clandestine chemist.
Seems like you would get more informative assistance on a site dedicated to this type of reaction since they are likely to have experience scaling up
these reactions, which can be extremely complicated in process chemistry.
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zed
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Seems to me, I've read posts claiming that this reaction does not work.
As for danger. If you are fairly inexperienced, the procedure might prove wildly dangerous.
Spend a few weeks searching the Archives. No point in beating a dead horse.
The synthesis of Nitroethane by various means, has been discussed at length.
But, be prepared for disappointment.
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Nicodem
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Quote: Originally posted by LD 50  | | Rather not link to the source, as it from a book that would be of interest to persons of ill repute. |
We do not tolerate quoting content without citing the reference - this is insulting to those who take the scientific method seriously. Read the forum
guidelines for more information.
Besides, that synthetic method was originally published nearly 60 years ago in DOI: 10.1021/ja01588a059. Do you really think we are so incompetent
that we cannot even search the literature?
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Nicodem
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Thread Moved
22-10-2014 at 08:46 |
Oxirane
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The reaction does produce a small amount of liquid with indicators that to nitroethane. I performed this synthesis several years ago when I tested out
other similar types of reagents, but aside from DMF I used DMSO solvent, and the total volume was something around 2 liters. The reaction scheme and
distillation involved using protective gases and heating purges to decontaminate any ethyl nitrite that might have been formed.
Finally the residue was distilled direclty off from pre-heated and CO2 inert purged DMSO on 1atm, and about 30mL of liquid boiling at 110-120C was
obtained. Past this, I had other things going in my life back then and actually forgot it for a long and I never performed any precision tests on it
if it really was nitroethane. But the reaction volume, compared to its yield does not encourage to use this synthesis if reagent is needed in any
other than analytical amounts.
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Scr0t
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Doesn't the ethyl halide react with the DMSO giving a crystalline mass?
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JAVA
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DMSO react with ethyl halide, this liberates a worse sulphur smelling gas. That procedure doesn't work.
Now back on topic about the DMF procedure.
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FedeJuninArg
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Hi,
did anyone try this?:
Method 18: Oxidation of alanine with permanganate followed by decarboxylation
Nitroethane via oxidation of alanine?
Theory
MeCH(NH2). COOH + 3(O) --> MeCH(NO2). COOH + H2O.
MeCH(NO2). COOH + NaOH --> MeCH(NO2). COONa.
MeCH(NO2). COONa + H2O --> MeCH2(NO2) + NaHCO3.
Procedure
A solution of potassium permanganate (0.3 mol) in water was made by dissolving 47.41 g KMnO4 in 400 mL hot water in a 1 L 3-necked flask fitted with a
reflux condenser, a stirbar[note 1], thermometer, and a 100-mL addition funnel. As the solution cools to room temperature fine crystals of KMnO4
crystallise out of solution[note 2]. A solution of alanine (0.1 mol, 8.91 g) in 65 mL of water was placed in the addition funnel and added dropwise
with stirring over a 20 minute period. The temperature slowly rose. When the addition was complete, the reaction mixture was heated to 60º over a
period of approximately 2 hours. 40 mL of acetone was added [note 3] and then the reaction mixture maintained at 70-85º [the sludge was extremely
viscous and the stirbar was of no use] for 2 hours. 0.1 mol sodium hydroxide in 20 mL of water was then added through the addition funnel.
Pause (to be completed).
The flask showed no sign of heating up after addition of the NaOH. By now the black/brown sludge will not mix (with the stir-bar). The next step
is to heat to 80-100C to decarboxylate any nitro-propionic acid and then to steam distil.
Notes:
1. An overhead stirrer is essential - the stirbar will get clogged with MnO2.
2. KMnO4 solubility is 1 in 3.5 parts of hot water and 1 in 14 parts of cold water.
3. The acetone was added to try to clear the sludge. I would have added more but I had second thoughts.
Refs:
1. Synthesis Of Aliphatic And Alicyclic Nitro Compounds; Org. Syn. p 131-132 [The Oxidation of Amines]
2. Organic Syntheses, Vol. 52, pp 77-82, 2-Metryl-2-Nitrosopropane and its Dimer, A. Calder, A. R. Forrester and S. P. Hepburn.
3. Vogel's Practical Organic Chemistry, 4th ed. P 564 'Nitromethane'.
Would it work with sodium dichromate?
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chemister2015
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Alpha-aminoacid oxidized to aldehyde, and not to nitroacid.
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nimgoldman
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Extracting the product with diethyl ether does not work very well as ether is miscible with DMF.
The procedure is slightly scaled down one from Rhodium Archive. However, Rhodium's procedure correctly uses pet ether (hexane can be used too).
Author of that book is of bad reputation, the book itself is badly written (lots of shamelessly copy-pasted texts from the internet), does not cite
sources, yields, nor melting points.
I made the mistake of following this procedure.
I think the nitroethane synthesis can be better carried out using iodoethane and silver nitrite (Systematic organic chemistry, by W. M. Cumming, 280, 1937) -
could this work with bromoethane as well?
Another viable option might be the dry distillation of sodium ethyl sulfate, but I haven't tried it.
[Edited on 17-10-2018 by nimgoldman]
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AJKOER
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C2H6 + HONO2 --H2SO4--> C2H5NO2 + H2O (see https://translate.google.com/translate?hl=en&sl=ru&u... )
I also suspect this reaction may proceed under UV photolysis of ethane in a mist of HONO2 in the presence of H2SO4 (to remove water) as:
HONO2 + UV --> .OH + .NO2 (see https://aip.scitation.org/doi/10.1063/1.439123 )
C2H6 + .OH = .C2H5 + H2O
.C2H5 + .NO2 = C2H5NO2
Related prior study of photolysis of pure ethane, see https://aip.scitation.org/doi/10.1063/1.1742620 and https://aip.scitation.org/doi/abs/10.1063/1.1673226 .
----------------------------------------------------------------------
A much more theoretically interesting path to me would be the action of the hydrogen atom radical (.H, see Buxton, and in particular, Eq (8) at https://pdfs.semanticscholar.org/d696/b35956e38351dd2eae6706... ) acting on ethanol/water in the presence of NO (see https://aip.scitation.org/doi/10.1063/1.439123):
C2H5OH + .H = .C2H5O + H2 (g)
.C2H5O + .NO = C2H5NO2
I would propose sourcing the .H from the action of Al/HCl with the hydrogen atom radical residing (temporarily) on the surface of the aluminum metal
(where this technique has been applied recently in the field of hydrometallurgy to leach minerals from ores, although I suspect that it would be more
useful in organic synthesis where the side product of hydrogen gas could be preferable to potentially problematic water, see my comments and
references at http://www.sciencemadness.org/talk/viewthread.php?tid=95047#...).
[Edited on 17-10-2018 by AJKOER]
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Melgar
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This procedure seems very dangerous to me. Dimethylformamide hydrolyzes into dimethylamine and formic acid fairly easily. In fact, dimethylformamide
is odorless when it's pure, and its smell comes from impurities of dimethylamine. Dimethylamine + nitrous acid gives you this fun compound:
https://en.wikipedia.org/wiki/N-Nitrosodimethylamine
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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myr
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Have you considered using phase-transfer catalysis? I know longer-chain nitroalkanes can be made with a biphasic toluene/water mixture with
tetrabutylammonium nitrite. doi 10.1080/00304948809356305 describes a similar procedure for 1-nitropropane. I personally never tried it, however.
Perhaps the tosylate ester won't alkylate DMSO like methyl bromide does (https://www.sciencemadness.org/whisper/viewthread.php?tid=15...)?
Is the nitroethane a reagent for another synthesis or the goal product? If it is the former, I would reconsider your synthetic route, if you would
care to inform us what it is.
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VSEPR_VOID
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This is a wonderful idea, but it can be improved. Use gallium alloyed with aluminium as a source of hydrogen radicals. The gallium will expose new
surface area. In addition, more Al can be added as needed.
I would be concerned about gallium reacting with any acids present. The reaction would be very slow, but it would eat up the aluminium and gallium,
reducing hydrogen radical product.
To form the NO in situ, you would need nitric acid and copper, or sulfuric acid and sodium nitrite with ferrous sulfate.
[Edited on 19-10-2018 by VSEPR_VOID]
Proposed Procedure
A rbf is charged with aluminium powder, gallium (liquid), ethanol, and sodium nitrite. The mixture is then stirred for some time to allow some
gallium-aluminium alloy to form
Then, a addition funnel and condenser is added and with gentle heating refluxed with the slow addition of sulfuric acid.
The heating discourages the formation of nitrous acid. To prevent oxidation of the NO, a tube from the condenser is led into a beaker of water;
allowing for the escape of gas, but not the entrance of oxygen.
Once the acid has been added, the reaction is left to cool and the rbf checked for the formation of a layer of nitroethane. If any ehtyl nitrite
formed, a simple bp check should find it.
Alternatively no gallium could be used, and instead HCl would be employed. The downside of this is that the aluminium would be reacted away quickly.
Gallium does react with sulfuric acid over time at higher temperatures, see my thread about gallium sulfate.
[Edited on 19-10-2018 by VSEPR_VOID]
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clearly_not_atara
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People using this method seem to consistently forget that nitrite scavengers like phloroglucinol are required for a good yield. This
is mentioned in the original paper which introduces the method.
Effective scavengers include resorcinol, phloroglucinol and catechol. I've wondered if paracetamol might be an effective OTC
substitute.
| Quote: | | Perhaps the tosylate ester won't alkylate DMSO like methyl bromide does |
It does. In fact, this is a synthesis of aldehydes given in an old chemistry textbook I have laying around somewhere.
| Quote: | | Rather not link to the source, as it from a book that would be of interest to persons of ill repute. |
Total Synthesis by Strike I'm pretty sure lol
[Edited on 19-10-2018 by clearly_not_atara]
[Edited on 04-20-1969 by clearly_not_atara]
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VSEPR_VOID
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| Quote: Originally posted by clearly_not_atara | People using this method seem to consistently forget that nitrite scavengers like phloroglucinol are required for a good yield. This
is mentioned in the original paper which introduces the method.
Effective scavengers include resorcinol, phloroglucinol and catechol. I've wondered if paracetamol might be an effective OTC
substitute.
| Quote: | | Perhaps the tosylate ester won't alkylate DMSO like methyl bromide does |
It does. In fact, this is a synthesis of aldehydes given in an old chemistry textbook I have laying around somewhere.
| Quote: | | Rather not link to the source, as it from a book that would be of interest to persons of ill repute. |
Total Synthesis by Strike I'm pretty sure lol
[Edited on 19-10-2018 by clearly_not_atara] |
Which method do you speak of?
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clearly_not_atara
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By "the method", I mean the alkylation of nitrite salts in DMF. The paper which introduces the method clearly states that nitrite scavengers
are required for high yield. Urea is also an important co-catalyst.
I've posted this at least six or seven times by now and I've never seen anyone even try to do the reaction correctly. It's like I'm
screaming at a wall. The stubbornness and impatience of people who are nonetheless willing to spend hours manipulating glassware is phenomenal.
"Unless appreciable amounts of both the alkali metal nitrite and the alkyl halide are in solution, no reaction occurs. With this restriction in
mind it is apparent why only in DMF and ethylene glycol, of the common solvents, does a reaction occur..."
"The addition of urea to DMF drastically increases the solubility of sodium nitrite. In reactions employing secondary alkyl iodides,
this is all that is required to provide the yieIds listedin Table I. with secondary bromides, and also cyclopentyl and cycloheptyl iodides, it
becomes desirable not only to add urea but also a nitrite ester scavenger. Compounds such as phloroglucinol, catechol and resorcinol can be
used for this purpose; of these phloroglucinol is the rnost effective. "
Of course Strike in his infinite wisdom decided that including the necessary catalysts in his write-up was not worth his time, and down the drain goes
all your DMF...
Attachment: kornblum1955.pdf (635kB)
This file has been downloaded 546 times
[Edited on 04-20-1969 by clearly_not_atara]
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S.C. Wack
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| Quote: Originally posted by clearly_not_atara | By "the method", I mean the alkylation of nitrite salts in DMF. The paper which introduces the method clearly states that nitrite scavengers
are required for high yield. Urea is also an important co-catalyst.
I've posted this at least six or seven times by now and I've never seen anyone even try to do the reaction correctly. It's like I'm
screaming at a wall. The stubbornness and impatience of people who are nonetheless willing to spend hours manipulating glassware is phenomenal.
[...]
Of course Strike in his infinite wisdom decided that including the necessary catalysts in his write-up was not worth his time, and down the drain goes
all your DMF...
|
mmmmm....what to say what to say...how about fuck you for making me correct OCR etc at the very least
TS2:
This next method was included with a [identical] submission by Ritter that appeared in the Theoretical section of this book.
"Ethyl bromide 32g, 26.0 ml (.3mol) or Ethyl iodide 46g, 24ml (.3mol) is poured into a solution of 250 ml Dimethylsulfoxide (DMSO) or N,N
Dimethylformamide or N-methylpyrolidone (DMSO preferred), 36 grams sodium nitrite (that's NaNO2 pyromaniacs, not sodium nitrate) and 52 grams
phloroglucinol dihydrate. This stuff is expensive but it can be recycled. Stopper aft this in a flask with a good magnetic stirring
bar and stir it in a room temp. water bath for 2 hours or.until an emulsion forms. At this point dump all into 600ml ice water and extract wWtwo
portions of 200ml methylene chloride. The MeCl2 extracts are washed w/water three times then dried w/ anhydrous magnesium sulfate then evaporated off
in a fractional distillation setup, collecting the fraction that boils at 113-116'C at atmospheric pressure as pure nitroethane. Expected yield about
20 grams. That's not a ton of product but this reaction can be scaled to any size you can dream of and yields will stay in the 80% range."
Kornblum et al.:
1-Bromooctane (58 g., 0.30 mole) was poured into a stirred mixture of 600 ml. of DMF and 36 g. of sodium nitrite (0.52 mole) immersed in a water-bath
maintained at room temperature; stirring was continued for 6 hours. The reaction mixture was then poured into 1.5 l. of ice-water layered over with
100 ml. of petroleum ether (b.p. 35-37'). The aqueous phase was extracted four more times with 100-ml. portions of petroleum ether after which the
extracts were washed with four 75-ml. portions of water and dried over anhydrous magnesium sulfate. The petroleum ether was removed by distillation
under reduced pressure through the column; heat was supplied by a bath whose temperature was gradually raised to ca. 65". Rectification of the residue
yielded 13.6 g. (29%) of 1-octyl nitrite (b.p. 37" (2 mm.)...and 28.2 g. (60%) of 1-nitrooctane (h.p. 60" (1 mm.)
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VSEPR_VOID
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It seems like the dimethyl sulfate or sodium ethyl sulfate method is much better. The later only requires lime, ethanol, drain opener sulfuri acid,
and sodium hydrogen carbonate to make the final product. Distillation of sodium nitrite with sodium ethyl sulfate yields nitromethane.
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S.C. Wack
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btw
A) Rhodium's nitroethane.kornblum.dmf.pdf (1956) and nitroethane.kornblum.dmso.pdf (57); no nitroethane but much more.
B) Instead of oxidizing alanine, nitroethane may be possible from NaNO2/HBr, neutralizing, more NaNO2, distilling.
C) A. B. and C. "It is so wild darling, it will end in tears"/"All the best parties do"
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nimgoldman
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| Quote: Originally posted by VSEPR_VOID | | It seems like the dimethyl sulfate or sodium ethyl sulfate method is much better. The later only requires lime, ethanol, drain opener sulfuri acid,
and sodium hydrogen carbonate to make the final product. Distillation of sodium nitrite with sodium ethyl sulfate yields nitromethane.
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Yes the sodium ethyl sulfate is the next method I will try. Making sodium ethyl sulfate is very easy.
The next viable alternative could be reacting iodoethane with silver nitrite. Preparing iodoethane looks straightforward but I wonder if this method can be modified to use bromoethane
(I have lots of it already synthesized). Silver nitrite can be made from more available silver nitrate and then recycled (expensive reagent).
The downside of the latter method is the production of relatively large amount of ethyl nitrite as a byproduct.
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chemplayer...
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We can testify that the ethyliodide + silver nitrite method works relatively well (captured in glorious technicolour over on Bitchute). Recycling the
resulting silver iodide back into silver metal and solid iodine is trickier but can be done with reasonable yields as well (another video), but don't
expect super high recycle rates. As a result it's an expensive method!
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VSEPR_VOID
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| Quote: Originally posted by chemplayer... | | We can testify that the ethyliodide + silver nitrite method works relatively well (captured in glorious technicolour over on Bitchute). Recycling the
resulting silver iodide back into silver metal and solid iodine is trickier but can be done with reasonable yields as well (another video), but don't
expect super high recycle rates. As a result it's an expensive method! |
For the silver is not a problem, but the ethyl iodide is. In the US red phosphorus is hard to get as the DEA will have a fit.
Can it be made without red phosphorus.
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