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Author: Subject: Nitroalkane syntheses ?
Joeychemist
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thumbup.gif posted on 21-1-2005 at 08:59
That book looks promising


Sparkgap, when you find time could you maybe scan the book and upload it to the ftp please???:);)

I'm sure we would all be gratefull:)
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sparkgap
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[*] posted on 21-1-2005 at 09:17


You're too formal. Call me sparky. ;)

Anyway, I don't have a scanner handy. I'll just quote the book after I read it cover to cover. I don't think all the syntheses Olah describes are appropriate for a makeshift lab, if you get my drift.

Anyway, it should be good overall. Olah learned quite a bit on this subject from Sir Christopher Ingold, the father of modern nitration chemistry.

sparky
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[*] posted on 17-5-2006 at 00:15


Quote:
Method 10: ethyl bromide, DMSO, NaNO2 and phloroglucinol dihydrate

By Ritter, in Strike's book- TSII.

32g or 26ml EtBr is poured into 250ml of DMSO with 36g NaNO2 and 52g phloroglucinol already present in solution.(Pglucinol is expensive but can be recycled) put on good mag. stirring and stopper the flask. Stir for two hours in emulsion form, then dump into a 600ml of ice water and extract twice with DCM. (2x200ml) dry the extracts withMgSO4 or CaCl2 the evap off the DCM. Distill and collect the fraction from 113-116°C--- yields about 20g of nitroethane (80%)(another ref says maybe over 90% consistently)
Other notes:catechol and resorcinol have the same nitrite scavenging abilities as phloroglucinol. And ethylene glycol can be used as a solvent. A simple NaOH wash of the final solution (nitroethane removed) will give the sodium salt of your phloroglucinol catalyst. Acidification of the solution will precip the catalyst for recovery by filtration.


This is from rhodium. Looks likequite simple. Resorcinol is easily available to me. If yiels are so go as stated... I will give it a shot. Maybe someone tried it before ? Comments ? Suggestions ?
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shocked.gif posted on 21-5-2006 at 02:57


Absolutely confused ! Tried to follow nitroethane synth in previous my post in this thread. dissolved NaNO2 and Resorcinol in 260ml DMSO and added Ethyl bromide at once...All liquid changed color from yellow to slight orange. Started to mix it manually for a few minutes and then left it to rest in dark place for 24h mixing it occasionally. After night at flat bottom flask was ......... See yourself : http://img163.imageshack.us/my.php?image=upsidedown1qw.jpg

Hard plastic like thing(almost the same as in red plastic synth with NaOH , CH2O and resorcinol...) I don't want to break that flask :o Someone wanna try it ?
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[*] posted on 21-5-2006 at 09:19


It has been said several times at The Hive that this procedure does not work and that the reaction mixture simply solidify to some unknown crap. I would assume it has to do with the fact that ethyl bromide is known to react with DMSO. Glycol has been proposed in certain Rhodium's pages, however ethyl bromide is not miscelabile with it. Rather use DMF instead.



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[*] posted on 27-9-2006 at 19:24


I thought of a potential route to nitromethane today, diazotize glycine, react with KI for the iodoacetic acid(which I think has other uses as well), followed up by a reaction with nitrite to form the nitroacetic acid(ala the standard chloroacetic acid procedure, but iodine should come off a bit easier, and introduction of iodine via diazotization is easier) which decomposes into nitromethane.

Or oxidize glycine somehow, but the glycine oxidation thread did not seem to have any results with this.
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[*] posted on 19-11-2006 at 13:48


Hi, having seen some idea's here and some references i dug up the synth for nitroethane by reacting sodium ethyl sulfate and NaNO2 under a catalyst of Kalium Carbonate.
I have seen some warnings about the formation of unstable nitrite esters which could form in a distillation setup.
I was wondering if someone could point out the dangers in this particular synthesis?

1.5 mole sodium nitrite (103.5g) is intimately mixed with 1 mole of sodium ethyl sulfate (158g) and 0.0625 moles of K2CO3 (8.6g). The mixture is then heated to 125-130?C, at which temperature the nitroethane distills over as soon as it is formed. The heating is discontinued when the distillation flow slackens considerably, and the crude nitroethane is washed with an equal amount of water, dried over CaCl2, and if needed, decolorized with a little activated carbon. The nitroethane is then re-distilled, collecting the fraction between 114-116?C. Yield 46% of theory

(another ref says max. 42%)
Chemical Abstracts, Vol 49, pg 836.
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[*] posted on 20-11-2006 at 05:15


There is an error in that method, read yourself (from one of the few good threads on WD):


Evil lurker:

Nitroethane, that substance which is so cheap at any chem supply house, but so damn hard to get. Making the stuff ain't very much easier than buying it from the recipes on the net.

The two OTC easiest ways, using sodium ethyl sulfate and diethyl sulfate as reagents are very hard and dangerous to manufacture. The problem lies in the water molecule the ETOH creates when it forms the ester. The apparatus looks plain scary to operate, and creates diethyl ether as a side product and the yields suck ass!

But now that problem has been fixed. Sodium ethyl sulfate can be easily prepared in the home laboratory from common sodium bisulfate found in pool pH down and 95% pure grain alcohol, and baking soda or sodium carbonate found in pH up.

113 parts by weight of sodium bisulfate and 20 parts by weight of pure grain alcohol are combined in a flask and brought to boiling upon which time the sodium bisulfate crystals disappear and sodium sulfate forms.

When the reaction has been completed, the flask was is immersed in an ice bath and vigorously stirred until the tempurature rapidly goes below 32.3C.

The formed sodium sulfate is thus filtered out leaving an anhydrous ethyl hydrogen sulfate/ethanol mix.

The excess ethanol is distilled off, and the ethyl hydrogen sulfate is neutralized with an appropriate quantity of sodium carbonate leaving sodium ethyl sulfate.

Simple... thats all there is to it! The secret to how it works is the excess sodium bisulfate when rapidly cooled below 32.3C forms the decahydrate, or Glaubers salt, and this sucks the water out of the reaction.

This is discussed futher in US Patent number 3,024,263.

Nitroethane can now be easily worked up according to this synth:

1.5 mole sodium nitrite (103.5g) is ... (here comes the synth you posted) ... Yield 46% of theory.

There ya have it folks, nitroethane cheap and dirty, from nearly all OTC chemicals.



Pelnicki:

Three QUESTOINS (which are good ones)

1. Does anyone know if the K2CO3 can be subst'd with Na2CO3 in the NaEtSO4 -> NitroEthane workup?

2. Or if the 95% "everclear" style ethanol can be subst'd with 95%/5% methylated denatured alcohol? (...)

3. Or for that matter, if the NaNO2 can be subst'd with KNO2? (...)



Bio:

The increase in yield brought by the addition of alkaline carbonate, all equal things besides, is thus manifest. The use of a potassium salt gives a more fluid product, by lowering of the melting point eutectic and increase in solubility in water. For this reason probably, the yield obtained with potassium carbonate is higher than that which the sodium carbonate gives, with equal molecular concentration. Moreover, in the presence of CO3Na2 or of CO3K2, the reaction is less exothermic, therefore easier to . Finally the proportion of secondary products: methanol, méthylamine, HCN, are appreciably reduced.

A proportion of 2.5 mol of CO3K2 per 100 mol of NO2Na, is 5% in weight, appears to be most favorable.

This applies to EtNO2 also and the dry distillation of EtHSO4 & NaNO2is not the best yielding procedure due to scorching and heat transfer etc problems.



Roy g biv:

The method detailed above is from Chemical Abstracts Vol 49 pg 836.
Below is info which may be of some use to dreamers. Extract from the
Hive by moo (may he or she receive all the blessings of the universe)
in Methods Discourse.

"The bees know that the nitroethane preparation procedure from sodium
ethyl sulfate given in rhodium doesn't give the the results expected.....
... because of the very terse abstract posted in Chemical Abstracts....
The actual method from the article referenced is a bit different....."

The following was added in the original article by moo.

Preparation of Nitroethane
by Gerard Desseigne & Henri Giral

The reaction flask is charged with:
26.5 g (0.0625 * 3moles) of tech grade K2CO3 dissolved in 137 g of water
320 g of 97% tech sodium nitrite
6 ml of cetyl-oleic alcohol or oleic alcoholm(antifoaming agent)
Vol of the mixture is about 420 mls
The mixture is heated on a bath at 130C with stirring. The addition funnel
is charged with 750 ml of an aqueous solution of 444 g (3moles) sodium ethyl
sulfate. The solution is added to the reaction mixture during 50-60 mins at a
suitable rate to keep the reaction mixture at 125-130C, with vigorous
stirring.
The distillation of the nitroethane begins when the addition is started.
When addition of NaEtSO4 is complete 100 mls of water is added during 10 mins.

The distillate separates into 2 layers. Can be distilled at 760mmHg with a distillation column. Distillation starts at 30C. All below 74C is discarded. Temp should settle
at 87C & distillation is stopped at 99.8C.

Yield of nitroethane:96 g (1.28 moles), 42.6% based on NaEtSO4



I tried both the dry distillation and the one described above (solutions mixed). Got less than half a ml each time, but then again I started with 2g each of nitrite and Na-ethylsulfate.

72 grams of NaEtSO4 are sitting in my dessicator at this moment. Let's see how it goes next time. BTW the EtONO danger is new to me. Oh and the NaEtSO4 was made from sulfuric, everclear, lime and soda as is described in Rhodium's "nitroalkane preparation FAQ".

What I don't understand are the temps for distillation: Since when does nitroethane come over at 87C under one atm?
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[*] posted on 3-12-2006 at 07:01


Im interested to see if anybody can get a workable nitroethane synth. I have been searching online and it seems that people get all the hardware in check and then they never post their results.
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[*] posted on 4-12-2006 at 08:28


"... and then they never post their results."

You know why? THERE IS NOT WORKABLE NITROETHANE SYNTH!

Just joking, but it definitely does not work as stated by most online sources, and is not really OTC:

- Isomerisation of ethyl nitrite is a myth, or so I have heard.

- Going via ethyl bromide/iodide plus sodium nitrite takes ages, needs DMF as a solvent, and the DMSO substitute again does not work since it reacts (same source, forgot who, but was an old bee), neither does glycol. Don't ask if the phloroglucinol addition makes it go as planned, anyway making alkyl halides as a pre-pre-precursor is no longer funny.

- Dry heating of NaEtSO4+NaNO2 is said to give hardly any yield "due to scorching and heat transfer problems"

- Mixing of solutions (see my post above) yielded even less. I tried again with 12g ethyl sulfate and 8g nitrite and got three drops at most, which dissolved on washing.

- Oxidation of ethylamine with m-chloroperbenzoic acid / dimethyldioxirane? Not really OTC.

I have not tried diethylsulfate + nitrite yet, but my hopes are low.
The same goes for EtBr or EtI + silver nitrite. I know it should work better than the sodium salt, but apart from having to make the halide first: working with no light, dry ether, 48-hour reaction, vacuum ... sounds fun.

So far my best (hahaha) yield was 1ml EtNO2 from 12g NaEtSO4 and 8g NaNO2, by mortar'ing it well together with 500 mg Na2CO3, then heating in an oil bath for an hour at 140C (oil). I doubt K2CO3 will make much of a difference, but I might try next time. What I suspect to bring yield up more is a high-boilling solvent to prevent scorching, perhaps combined with urea.

If the next two steps have the same yield (17%), there will be 2 mmol nitropropene left, and from there 400 µmol phenylisopropylamine. Could as well drink a coffee :P
Or stick to explosives :cool:

[Edited on 4-12-2006 by Boomer]
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[*] posted on 4-12-2006 at 16:03


.........THERE IS NOT WORKABLE NITROETHANE SYNTH!.........

Huh? The 42.6% yield quoted above ain;t far off from the yiekd
just reported by one of our members.
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[*] posted on 4-12-2006 at 17:33


Reference Information



A New Method for the Synthesis of Aliphatic Nitro Compounds
NATHANK ORNBLUMHA, ROLD0. LARSONR, OBERTK . BLACKWOODDA, VIDD . MOOBERREYU, GENEP. OLIVETOA ND GALENE . GRAHAM
Journal of the American Chemical Society 1956, vol:78 iss:7 pg:1497


Abstract
A simple new synthesis of primary and secondary nitro compounds which involves treating alkyl halides with sodium nitrite in dimethylformamide is described; 55-62% yields of pure nitro compounds are obtained.

[Edited on 5-12-2006 by solo]

Attachment: A New Method for the Synthesis of Aliphatic Nitro Compounds1, 2.pdf (661kB)
This file has been downloaded 2745 times





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[*] posted on 4-12-2006 at 17:57


Quote:
Originally posted by Boomer
snip

[Edited on 4-12-2006 by Boomer]


Would the use of a vacuum or larger amounts of reactants help give a higher yeild of nitro ethane? Or how about combing the synthesis of ethyl hydrogen sulfate with the sodium nitrite addition. This way the water that is formed from the bisulfate/EtOH reaction can dissolve the nitrite and NaEtSO4 and react to form Sodium sulfate and nitroethane. The Sodium sulfate well then form a hydrate with the water.




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[*] posted on 14-7-2007 at 15:07


Quote:
Originally posted by Boomer
There is an error in that method, read yourself (from one of the few good threads on WD):


Evil lurker:

Nitroethane, that substance which is so cheap at any chem supply house, but so damn hard to get. Making the stuff ain't very much easier than buying it from the recipes on the net.

The two OTC easiest ways, using sodium ethyl sulfate and diethyl sulfate as reagents are very hard and dangerous to manufacture. The problem lies in the water molecule the ETOH creates when it forms the ester. The apparatus looks plain scary to operate, and creates diethyl ether as a side product and the yields suck ass!

But now that problem has been fixed. Sodium ethyl sulfate can be easily prepared in the home laboratory from common sodium bisulfate found in pool pH down and 95% pure grain alcohol, and baking soda or sodium carbonate found in pH up.

113 parts by weight of sodium bisulfate and 20 parts by weight of pure grain alcohol are combined in a flask and brought to boiling upon which time the sodium bisulfate crystals disappear and sodium sulfate forms.

When the reaction has been completed, the flask was is immersed in an ice bath and vigorously stirred until the tempurature rapidly goes below 32.3C.

The formed sodium sulfate is thus filtered out leaving an anhydrous ethyl hydrogen sulfate/ethanol mix.

The excess ethanol is distilled off, and the ethyl hydrogen sulfate is neutralized with an appropriate quantity of sodium carbonate leaving sodium ethyl sulfate.

Simple... thats all there is to it! The secret to how it works is the excess sodium bisulfate when rapidly cooled below 32.3C forms the decahydrate, or Glaubers salt, and this sucks the water out of the reaction.

This is discussed futher in US Patent number 3,024,263.

Nitroethane can now be easily worked up according to this synth:

1.5 mole sodium nitrite (103.5g) is ... (here comes the synth you posted) ... Yield 46% of theory.



Why is it better? The sodium bisulfate decompose in the alcohol in sulfuric acid and sodium sulfate. The only reason is that the sodium sulfate is cheap than the concentrated sulfuric acid.

Why does the method that proposes rodhium use CaCO3? For remove the sulfuric acid without reacting?

[Edited on 14-7-2007 by Filemon]
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[*] posted on 21-2-2010 at 00:38


It's repeated in many sources that the reaction of sodium nitrite with alpha-bromo acids can produce nitroalkanes in about 50% yield, but the reaction is only useful for the lowest two of the series. Contrary to e.g. Vogel, the synthesis appears to work reasonably well up to 3-carbon nitroalkanes rather than only 2-carbon, at least according to Auger's original paper on the subject.

There's a brief translation of the nitroethane passage from Auger's paper in the Rhodium nitroethane synthesis compendium.

The original text:
Quote:
Acide α bromopropionique et azotite de sodium:— 20 gr. d'acide sont saturés par une solution à 20 0/0 de carbonate de potassium, en présence de phtaléine; on ajoute alors 20 gr. d'azotite de sodium, et le liquide formant environ 100 cc. est introduit dans un ballon à distiller de 250 cc., dont le tube adducteur est soudé très bas pour permettre une rapide distillation. Vers 100 cc. la réaction commence; on éloigne la flamme et continue la distillation après l'apaisement de la première réaction. Lorsqu'il ne passe plus de gouttes huileuses, on décante l'huile distillée, qu'on sèche sur le chlorure de calcium et rectifie. Rendement 50 0/0 de la théorie.


The Rhodium translation:
Quote:
Add 20g of the acid to a solution of K2CO3 in the amount of base that causes the solution to be basic to phenolphthalein. The add 20g of NaNO2--there should be approx. 100ml of solution. Place in a 250ml rb flask and distill quickly- the first 100ml will come over before the rxn takes place. Then the nitroethane comes over. Distill until no more product comes over.(don't distill to dryness)


The version I pieced together with machine translation and some slight knowledge of French:
Quote:
20 g of acid are saturated by a 20% solution of potassium carbonate in the presence of phenolphthalein, then 20 g of sodium nitrite, and the liquid forming about 100 cc. is introduced into a distillation flask of 250 cc., and the conducting tube is joined very low for a quick distillation. Around 100 cc. the reaction begins, we remove the flame and continue the distillation after the easing of the first reaction. When no more oily drops pass over, decant the oil distilled, dry over calcium chloride and rectify. Yield 50% of theory.


I am certainly missing some idiom, because even with the help of a French-English dictionary for chemists (thanks, S.C. Wack) I cannot satisfactorily interpret all of the directions in this passage. Or, rather, I think I understand what should be done, but it is in spite of (rather than because of) my ability to translate the French. I would appreciate it if a fluent French reader could see how the translations compare.

I did a complete OCR cleanup and translated it all using machine translation + the dictionary + the lingering memories from high school French classes. It was slow going, but at least it appears feasible to mostly-understand old procedures in foreign languages this way if an English translation has not already been published for my convenience.

Attachment: auger-nitroalkane.pdf (83kB)
This file has been downloaded 903 times

Attachment: auger-nitroalkane-en.pdf (82kB)
This file has been downloaded 1012 times

Attachment: auger-pageimages.pdf (236kB)
This file has been downloaded 735 times





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UnintentionalChaos
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[*] posted on 21-2-2010 at 06:33


Injecting my marginally relevant experience here, but I have run the nitromethane synthesis from orgsyn exactly as stated except for a 50% scaledown and can report that it works with the reported 35% yield. You'll need to have a thermometer *in* the liquid because the reaction does indeed take off around 80C and self-heats for quite a while. This temperature might be a bit different for higher homologues and it probably will not self-distill as well.

Obviously, watch out when attempting to scale up due to the exotherm and gas release. I strongly suspect that the 50% yield quoted in the above paper is rather optimistic.

[Edited on 2-21-10 by UnintentionalChaos]




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biggrin.gif posted on 14-11-2010 at 01:22
benzaldehyde or MeO2 analogue been lonely too long ?


http://www.youtube.com/watch?v=5LxC3M-Yngs&fmt=18 Harry Nilsson - Put The Lime In The Coconut

http://www.youtube.com/watch?v=HpmJl0pdwyY&fmt=18 Lonely Too Long

http://www.youtube.com/watch?v=SBEomCtCujw&fmt=18
The Only Living Boy In New York

http://www.youtube.com/watch?v=sfv3kBzJZgU&fmt=18 One Trick Pony

http://www.youtube.com/watch?v=Rkgozdtsh_g&fmt=18 Groovin'

http://www.youtube.com/watch?v=WrwhfhncPfM&fmt=18 Beautiful Morning

http://www.youtube.com/watch?v=Hfhk2WxfV2c&fmt=18 People Got To Be Free

http://www.youtube.com/watch?v=o4fWN6VvgKQ&fmt=18 Get Together

Maybe these nitroethane related threads need merging or should be made into a compendium .....

Anyway not to be dismayed by disorganized channels of information , here is some supporting reference on the improving of yields gotten from the reaction of sodium ethylsulfate and sodium nitrite, by means of using sufficient water to help solublize and emulsify the reactants, with
the water including some sodium carbonate, or perhaps alternately sodium bicarbonate or sodium borate, to buffer
the pH of the reaction higher and oppose the byproduct formation of nitrous acid and ethyl nitrite which are undesired, raising the yield of nitroethane to 35% which
compares more favorably with the 65% yield by the alternative diethylsulfate and sodium nitrite reaction, which is also an emulsion reaction method. See article attached
Preparation of nitroethane, JCS 1944, 24-25.

A machine translation follows for the attached patent AT76500. Also attached is the Swiss issued parallel patent CH75523. These two patents appear to be equivalents of the original patent DE294755. The machine translation is not very clear, but is helpful.

Machine translation of AT76500
Method to the representation of nitromethane and its homologous one.
The method aims at one probably-files relative and technical light feasible representation method possible from nitromethane and its homologous one to to make, bodies, which can serve as valuable starting material for other chemical compounds, particularly for aliphatic amines. The method is based to bottom suitable conditions taking place action of approximate equivalent amounts of nitrous-acidic salts on that on alkyl-sulfur-acidic salts. This principle of the method is not in as much new as for the particular case of the action of sodium nitrite on ethyl-sulfur-acidic potassium already from that years 1878 a publication of L: : uterbach is present (reports of the German chemical society, Bd. 11, S. 1225).
This found, indicates Nitroäthan with the dry distillation of a mixture of the salts mentioned the bottom Reaktiocs products also however as yields for in many way to implemented experiments only amounts to 6% of the theory at Nitroäthan. Furthermore years have 1907 Prafulla Chandra Ray and Panchanan Neogi in (Proc. OF the chem. ones. Soc., Londen, Bd. 25, S. 259) a more general study over the action of Alkali-und alkaline-earth nitrites on various salts of the ethyl sulfuric acid published. It observed beside the known reaction products also the formation of small amounts of Nitrobutan. Experiments to the representation of other Nitroparaffine on the basis of the mentioned method do not seem to be made. It could not stress also the method for the representation of the Nitro of ethane practical interest, if it did not succeed to improve the yields whole significant.
It has itself now shown that one is by a changed operation, which forms the subject-matter of the invention indeed in the conditions, to bring the yields compared with the surprising high achieved of loud brook with Nitroäthan z. B. on approximately 35%, with nitromethane even on over 50% of the theory, against what they sink with higher homologous ones however. If one dampens the fine mixture of nitrite and alkyl-sulfur-acidic salt with as much water that with gentle heating, with approximately 50 to 600, an aqueous thin, milky liquid develops, then something already occurs a reaction over 100 ', so that with that water vapors much Nitroveibindung iiberdestilliert. By the liquefaction of the salt mixture will the reaction between the two salts obviously significant facilitated, now however whole particularly intimate mixed residue become from that finally drying can then still other amounts of the Nttrokörpens by somewhat stronger egg hitzen to be driven out.
The water additive alone is however still no sufficient prerequisite to the achievement of bestmöglichster yields. The alkylschwefelsaurel1 of salts decomposes with presence of little water, thus in concentrated solution. with the heating light bottom formation of free sulfuric acid and/or. acidic sulfates and, once more acidic become, this decomposition of the salt continues to walk then very rapid. Thus once the amount at alkyl-sulfur-acidic salt reduced, necessary for the reaction, becomes and then makes the formed sulfuric acid from the nitrite salpetjige acidic ones free, those, like known formation of Nitrosäuren responsive, bottom in the Entstehungszustacd with primary Nitro paraffins. Both procedures decrease thus. the yield at Xitroparaffinen. If one prevents therefore of the reaction mixture, an other increase of the yield occurs. This effect becomes now actual achieved by addition of a suitable alkali. Corroding alkalis are however not particularly suitable. probably however alkaline responsive salts very much weak acids, like Kaliumkabonat, sodium carbonate, borax and similar salts, with those a release of this weak acid no formation of nitrous acid caused. One will thus dampen the mixture of the salts mentioned by alkyl-sulfur-acidic salt and nitrite not with pure water, but with a solution of soda or another. Already relatively small amounts at alkali are sufficient, in order to ensure a permanent alkaline reaction of the salt mixture with the distillation.
An unnecessary large excess at alkali is to be avoided natural. Used one sodium carbonate. like that 5 to 7% is theoretical sulfuric acid complete sufficient contained by the weight the salt alkyl-sulfur-acidic in that.
It is easily apparent that the alkali additive plays whole other roller here. as with methods likewise working with alkali rzur representation of nitromethane by KnnMrkuug of C'hloressigsäure on nitrite. With this method the alkali serves only for it.
EMI1.1
<Desc/Clms PAGE NUMBER 2>
Amounts at alkali used and are these the Zersetzlichkeit of the alkyl-sulfur-acidic salts impairing the yield at Nitroalkyl by waters if possible preventing.
EMI2.1
to against 20 (y to rise leave. The distillate separates into an aqueous and an oily layer.
The latter consists to a large extent of Nitroäthan, which swims however due to a content at specific lighter compounds, acetaldehyde and ethyl nitrite, but ordinary on the water. Also this contains acetaldehyde. The pure representation of the Nitroäthans squinted then more other after known methods. With the fractionation can become all between 1060 and 1150 turning into as pure Nitroäthan considered. Small amounts of a dark remain
EMI2.2

In whole similar manner one proceeds with the preparation of nitromethane and nitropropane. With the representation of the first insignificant amounts of ISO nitrile do not arise, which give one to the escaping gases (Metbylnitrit) as well as the crude nitromethane much unpleasant odor. The elimination of the ISO nitrile offers however no difficulties.
The here described method is substantial various of the known method from Walden to the representation of nitromethane by action of dimethyl sulfate on Kaliumnitrit with presence of water (reports of the German chem. Society, 40 (1907). S. 3216).
This reaction runs after Walden in the cold in the sense of the equation
EMI2.3
and to Waiden as yield nitromethane receives 50 to 57% of the amount calculated from this. Here thus only a methyl group changes into the approximate same yield as with the method after present invention in nitromethane. Walden turns thereby still another large excess
EMI2.4
CSU it would have again plentiful amounts old nitromethane obtained after the method of the present invention. Obviously he did not foresee the possibility of such a reaction.
Also the water additive plays a various roller with the two methods. With the method after Waiden the water is once the violence of the action of dimethyl sulfate on dry nitrite moderate, furthermore by the reaction the formed, methyl sulfur
EMI2.5
PATENT CLAIMS:
1. Method to the representation of nitromethane and its homologous one by action of nitrous-acidic on alkyl-sulfur-acidic salts, characterised in that one the salt mixture as much water adds that with gentle heating liquefaction of the mass milchigejt to a aqueous-thin, liquid occurs.

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[Edited on 14-11-2010 by Rosco Bodine]
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AndersHoveland
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[*] posted on 29-7-2011 at 16:29


Catalytic nitration of alkanes with nitric acid was first successfully achieved by the use of N-hydroxyphthalimide (NHPI) under mild conditions; the key to the present nitration was found to be the in situ generation of NO2 and phthalimide N-oxyl radical by the reaction of NHPI with nitric acid.


http://pubs.rsc.org/en/content/articlelanding/2001/cc/b10237...
Sounds very interesting, and potentially useful.




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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[*] posted on 29-7-2011 at 22:42


Quote: Originally posted by chemoleo  
I was wondering, not for the first time, which general methods are available for the production of simple nitro alkanes.

I can see two routes for this:

1) R3C-NH2 --> oxidise --> R3C-NO2.

2) R3C-Cl/Br/I + NO2- --> R3C-NO2 + Cl/Br/I-

where R is H or whatever.

I know that both reactions have been shown to work, but particularly in the latter case I failed to find references as to what conditions exactly need to be employed.
For instance, tetranitromethane can be made by the reaction of iodopicrin I3CNO2 with AgNO2. What reaction conditions are supposed to be employed there? I.e. iodopicrin is surely insoluble in water, so to facilitate the reaction with silver nitrite would be tricky. Equally, how about the reaction of chloroform with AgNO2? The former is definitely not soluble, so how can one go about to get the reaction to work?
Alternatively, how about chlorination of ethylene to form 1,2 dichloroethane... and to react this with AgNO2.
I take it the reason why the Ag, rather than the Na/K nitrite is chosen is because the former is highly insoluble, thus shifting the equilibrium of the reaction faster to the right.

As to reaction scheme 1) - the oxidation of amines - what are the generic conditions there? I.e. what if the starting compound was ethylenediamine H2N-CH2CH2-NH2? It's a liquid, soluble in H2O and highly basic.

Any help on this would be appreciated.:)


[Edited on 21-11-2006 by chemoleo]


Your answers are still unsolved after 7years!

I know that AgNO2+iodoethane in ether works but it takes nearly 40 hours under reflux and the yields where small. Though the inventor Victor Meyer did this reaction with continious stirring in the cold.

A byproduct is formed the (oxy)nitrosoethane (ethyl nitrite) which isn't a nitrite ester in mechanistic way, rather a arises from a substitution reaction.

Note that ONO is an ambident nucleophile, where you get the unwanted byproduct if the more electronegative oxygen is attacking. But I think that the weak bond of Ag with oxygen, the bond that get formed with an ether between the small(!)Ag ion and the oxygen of the ether serves as stabilizing effect - like in Grignard reactions. The reaction is best done by low temperatures to prevent ionisation of one of the oxygen atoms in ONO. On the cold, the lone pare on the nitrogen can attack with the slightly positive carbon of your haloalkane.

In the other cases a aprotic, polar solvent is used. These have the tendency to make te lone pair on the N even more reactive. Meanwhile, the positive charge of the sodium decreases so far that you don't have to be scared to get ionisation and thus attacking of the oxygen on ONO. What probably happens is that in that case the negative charge is spreading out over the 2 oxygen atoms of ONO and thus the neg. charge is delocalised, making the lone pair on the nitrogen even a better nucleophile.

Again, do this reaction in the cold, with stirring and in the last case it is better to simulate the reaction time, the shorter - the better. since nitroethane is volatile. Only solvent extraction with low boiling peth works to isolate your nitroalkane.

ID of nitroalkanes could easy be done by adding NaOH to nitroalkanes and then yellow crystals are formed. Decomposion of this with conc. H2SO4 gives in the case of nitroethane the odour of acetaldehyde. Nitroethane has a pleasant smell of marzipan, but formes an azeotropic mixture with water!


where did you find the following route?:

1) R3C-NH2 --> oxidise --> R3C-NO2

Have some members tried it?




Good to be wrong
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[*] posted on 2-3-2013 at 11:35


Hi there! I want to synthesize nitroethane using one of the schemes described here, but i'm a bit confused about the methods. I was wondering if someone could give me a hand?

Firstly, I want to start with sodium ethyl sulfate. This will be synthesized either by reacting sulfuric acid with ethanol, or sodium bisulfate and ethanol, as described by Boomer. Now, NaEtSO4 is a solid, yet no mention is made in either of the NaEtSO4 synthesis methods about how to recrystallize the compound.

I've seen some methods of synthesizing NaEtSO4 from H2SO4 and EtOH by heating under reflux, and some (wikipedia ethyl sulfate) say that the temp of the exothermic reaction must be kept below 170oC to prevent the NaEtSO4 decomposing back to H2SO4. I'm not sure where to go here ... whichever way I go I would then add Na2CO3, filter off the carbonate salt and then gently boil off the water to leave the NaEtSO4 salt. How does that sound?

Moving onto the sodium bisulfate method, Boomer quote Evil lurker who says:

"The formed sodium sulfate is thus filtered out leaving an anhydrous ethyl hydrogen sulfate/ethanol mix.

The excess ethanol is distilled off, and the ethyl hydrogen sulfate is neutralized with an appropriate quantity of sodium carbonate leaving sodium ethyl sulfate."

Well leaving the sodium ethyl sulfate in what? If it is anhydrous, and the ethanol has been boiled off, what is it dissolved in?

I will then react the NaEtSO4 and NaNO3 by dry distillation to try and produce nitroethane. The yields seem to vary depending on who you ask, but i'm going to give it a go. I assume that the two solids are mixed with stirring and heat, and that a vapor is produced which condenses in the distillation apparatus?

[Edited on 2-3-2013 by thebishop]
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[*] posted on 5-3-2013 at 02:21


If any of you can obtain some N-hydroxyphthalimide, you should be able to get nitric acid to react with methane/ethane/propane at room temperature. The N-hydroxyphthalimide acts as a catalyst, so you only need a very small ammount. It procedes through a radical mechanism.

"Nitration of alkanes with nitric acid catalyzed by N-hydroxyphthalimide", Shinji Isozaki, Yoshiki Nishiwaki, Satoshi Sakaguchi, Yasutaka Ishii, Chem. Commun., Issue 15, 2001, 1352-1353


If you think about it, if just the NHPI is mixed with nitric acid, there should be an equilibrium of radicals simultaneously forming and reacting.
It is not all that unbelievable that radicals can exist in equilibrium. It is well known in solutions of NO2 in water (as there is a tiny equilibrium with HNO3 and nitric oxide, a radical itself).

And I am sure the aromatic ring on the NHPI must be nitrated to some extent in nitric acid, but that is really not of any importance here.

The sturcture of NHPI is
H4C6(C=O)2NOH

you can easily see how the hydroxylamine group would get oxidized by the nitric acid to a radical =N-O•

It is not just nitric acid that can be used. "Modern Oxidation Methods", by Jan-Erling Bäckvall, mentions that in the presence of NPHI, NO2 can be used to nitrate cyclohexane, with a 70% yield under air (apparently the presence of oxygen improves the yields), 70 °C, reaction time 14 hours.

[Edited on 6-3-2013 by AndersHoveland]
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[*] posted on 5-3-2013 at 08:50


And where do you have the reference?
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[*] posted on 5-3-2013 at 11:13


What about electrolytic oxidation? There's a book in the ScienceMadness library that I read a few weeks ago that mentioned electrolyzing aniline to nitrobenzene (which might apply to other amines), but sadly whenever I try to access it (or any other book in the library) I get error 404.
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[*] posted on 5-3-2013 at 17:53


Quote: Originally posted by thebishop  
I will then react the NaEtSO4 and NaNO3 by dry distillation to try and produce nitroethane. The yields seem to vary depending on who you ask, but i'm going to give it a go.


This won't make any nitroethane; and it is likely to blow up for reasons mentioned here.

Quote: Originally posted by AndersHoveland  
If any of you can obtain some N-hydroxyphthalimide, you should be able to get nitric acid to react with methane/ethane/propane at room temperature.


The reaction is not at room temperature (60 C) and it's done under argon (one example was under air) for 15 hours, though the original reference basically only showed this to work in cycloalkanes, and one longer chain alkane. The reference is below.

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[Edited on 6-3-2013 by Formatik]
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[*] posted on 5-3-2013 at 19:57


Well ethylene is widely available. Might be able to produce it cheaply by pyrolysis of HDPE.

Addition of HNO2, across the double-bond might work in some universe.
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