Sciencemadness Discussion Board

Preparation of nitroethane

LD 50 - 21-10-2014 at 05:32

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?

LD 50 - 21-10-2014 at 06:37

Rather not link to the source, as it from a book that would be of interest to persons of ill repute.

LD 50 - 21-10-2014 at 07:41

Thanks solo, I saw your posts.

Chemosynthesis - 21-10-2014 at 08:54

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.

zed - 21-10-2014 at 15:49

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.

Nicodem - 22-10-2014 at 08:46

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?

Oxirane - 22-10-2014 at 08:57

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.

Scr0t - 22-10-2014 at 10:39

Doesn't the ethyl halide react with the DMSO giving a crystalline mass?

JAVA - 26-10-2014 at 10:12

Quote: Originally posted by Scr0t  
Doesn't the ethyl halide react with the DMSO giving a crystalline mass?


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.
java

FedeJuninArg - 18-2-2015 at 18:29

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?

chemister2015 - 26-2-2015 at 17:01

Alpha-aminoacid oxidized to aldehyde, and not to nitroacid.

nimgoldman - 16-10-2018 at 15:31

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]

AJKOER - 16-10-2018 at 17:23

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]

Melgar - 16-10-2018 at 18:08

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

myr - 17-10-2018 at 11:09

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.

VSEPR_VOID - 19-10-2018 at 06:42

Quote: Originally posted by AJKOER  
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]


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]

clearly_not_atara - 19-10-2018 at 11:27

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]

VSEPR_VOID - 19-10-2018 at 11:35

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?

clearly_not_atara - 19-10-2018 at 11:59

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 553 times

S.C. Wack - 19-10-2018 at 14:53

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.)

VSEPR_VOID - 19-10-2018 at 21:55

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.

S.C. Wack - 20-10-2018 at 07:47

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"

nimgoldman - 20-10-2018 at 14:18

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.


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.

chemplayer... - 23-10-2018 at 05:35

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!

VSEPR_VOID - 23-10-2018 at 09:12

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.

Elrik - 23-10-2018 at 09:28

I'll be needing some dioxane next year and so have been looking for uses for the byproduct acetaldehyde. I've already got enough nitroethane, but this is one potential route people could use.

• make useful dioxane and also save the acetaldehyde. Adding a solvent that wont sulfonate, like heptane, to the ethylene glycol/sulfuric acid may increase acetaldehyde yield at the cost of dioxane.
• buy hydroxylamine or make it from nitrite and bisulfite or metabisulfite, use it to make acetaldehyde aldoxime
• dissolve acetaldehyde aldoxime in glacial acetic acid, add perborate, and gently heat for a few hours to oxidize it to nitroethane
• add some water, distill over the nitroethane-water azeotrope, salt it, wash the organic layer with saturated salt water, dry with calcium chloride and distill the nitroethane.

chemplayer... - 23-10-2018 at 16:11

For ethyl iodide without red P you have two choices:

1. Use ethanol, KI and phosphoric acid together.
2. Use aluminium foil in place of the red P (limited yield).

We've done both and they both work (iodine is fairly easy to recycle from the reaction mixtures). Be prepared for patience and a slow reaction in both cases however with many hours of distillation of the reaction mixture to get a reasonable yield.

AJKOER - 26-10-2018 at 05:34

Based on my prior research (see extract below for references on the commercial metallurical application on the cited technique), I would speculate that one may be able to improve the aluminum foil approach to ethyl iodide by imbuing the surface of the added Al with the hydrogen atom radical (where the •H is created from a prior reaction of say NaOH on Al). Further, apply sunlight to dry KI resting in EtOH, as it is photosensitive. My take on some of the possible chemistry:

•H + EtOH --> H2 (g) + EtO• (see Buxton's related Eq (6) at https://pdfs.semanticscholar.org/d696/b35956e38351dd2eae6706... )

The above reaction also advantageously reduces the formation of problematic water, however, it is a much slower reaction than occurrs with the hydroxyl radical.

I- + hv --> •I + e- (see Buxton Eq (17))

•H + •I = HI

HI + EtOH = H2O + EtOI

EtO• + •I = EtOI

Problematic reactions that could reduce yield:

EtOI + •H = EtO• + HI

EtOI + e- = EtO• + I-

2 Al + 6 EtOH --> 2 Al(EtO)3 + 3 H2 (g)

Al + 3 •H +3 EtOH --> Al(EtO)3 + 3 H2 (g) (see below)

In the presence of water and any created Al(EtO)3 :

2 Al(EtO)3 + 3 H2O = 2 Al(OH)3 + 3 EtOH

HI (aq) = H+ + I-

H+ + e- = •H

H2O + e- = •H + OH- (slow)

Al + 3 OH- --> Al(OH)3 + 3 e-
.....

Prior thread citation (link: http://www.sciencemadness.org/talk/viewthread.php?tid=97948#... ):
Quote: Originally posted by AJKOER  
Here is a suggested path to make aluminium isoproxide without using any mercury, basically follow a cited path (see Wikipedia, https://en.wikipedia.org/wiki/Aluminium_isopropoxide#Referen... ):

2 Al + 6 iPrOH → 2 Al(O-i-Pr)3 + 3 H2 (g)

However, I would suggest to first treat the Al metal with either NaOH and HCl. As I discussed previously (see my comments on •H at http://www.sciencemadness.org/talk/viewthread.php?tid=40137#... ), this may imbue the surface of the Al with the hydrogen atom radical (•H). Target reaction to possibly accelerate product formation:

•H + iPrOH ---> •O-i-Pr + H2 (g) (see related Eq (6) at Buxton work at https://pdfs.semanticscholar.org/d696/b35956e38351dd2eae6706... )

Al --> Al3+ + 3 e-

•O-i-Pr + e- --> O-i-Pr-

Net:

Al + 3 •H +3 iPrOH --> Al(O-i-P)3 + 3 H2 (g)

I would expect the above reaction system to have a higher reaction rate and, upon collecting evolved hydrogen over water, twice the volume of generated H2 per mole of consumed Aluminum compared to the Wikipedia cited equation.

[Edited on 27-10-2018 by AJKOER]

VSEPR_VOID - 26-10-2018 at 10:11

Quote: Originally posted by chemplayer...  
For ethyl iodide without red P you have two choices:

1. Use ethanol, KI and phosphoric acid together.
2. Use aluminium foil in place of the red P (limited yield).

We've done both and they both work (iodine is fairly easy to recycle from the reaction mixtures). Be prepared for patience and a slow reaction in both cases however with many hours of distillation of the reaction mixture to get a reasonable yield.


I tried making ISP iodide by that method and failed. I used I2, Al, and the anhydrous alcohol.

S.C. Wack - 26-10-2018 at 15:59

Quote: Originally posted by VSEPR_VOID  
I used I2, Al, and the anhydrous alcohol.


No HI no iodide.

Melgar - 26-10-2018 at 20:15

Quote: Originally posted by S.C. Wack  
Quote: Originally posted by VSEPR_VOID  
I used I2, Al, and the anhydrous alcohol.


No HI no iodide.

Al + I2 will generate some HI. After all, anhydrous AlI3 + H2O certainly does. The problem is that you get crap like AlOI and AlI2OH that interferes with the reaction and prevents a lot of the iodine from reacting.

You can do this reaction with phosphoric acid and KI, distilling out the alkyl iodide as it forms. That certainly seems a lot cleaner than screwing around with amphoteric aluminum compounds.

S.C. Wack - 27-10-2018 at 07:22

Quote: Originally posted by Melgar  
After all, anhydrous AlI3 + H2O certainly does.


Quote: Originally posted by VSEPR_VOID  
I used I2, Al, and the anhydrous alcohol.


*drums fingers*

nimgoldman - 12-2-2019 at 22:49

Quote:

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.


One way around might be first producing HI using phosphoric acid and KI, then reacting HI with ethanol, yielding ethyl iodide.

However, ethyl bromide might be usable too, only requiring much longer reaction time.

My attempts for Victor-Meyer reaction failed with both EtBr and EtI, producing only very little nitroethane (like 1-2 milliliters instead of 15-30 mL expected). I am still looking up why that failed...

Jackson - 13-2-2019 at 10:07

I know this has probably been discussed before, and probably isn’t possible, but could nitroalkanes be made by the oxidation of the alkylamine using pottasium permanganate? For example, could nitroethane be made from ethylamine and potassium permanganate? Sounds like probably a no but if it is possible then that’s pretty cool and potentially useful.

Tsjerk - 13-2-2019 at 10:44

Quote: Originally posted by Jackson  
I know this has probably been discussed before, and probably isn’t possible, but could nitroalkanes be made by the oxidation of the alkylamine using pottasium permanganate? For example, could nitroethane be made from ethylamine and potassium permanganate? Sounds like probably a no but if it is possible then that’s pretty cool and potentially useful.


You would have known if it was possible.

There are some less OTC methods though. They work for aryl-amines though

https://www.organic-chemistry.org/synthesis/N2O/nitrocompoun...

[Edited on 13-2-2019 by Tsjerk]

clearly_not_atara - 13-2-2019 at 13:55

So if you can deal with NOx gases, there's a pretty simple method from anise oil (anethole) which is OTC:

anethole + N2O3 -> anethole pseudonitrosite dimer + KOH -> 2-nitroanethole
https://erowid.org/archive/rhodium/chemistry/pseudonitrosite...

Incidentally, I'd guess that crude nitrite made by pyrolysis of nitrates can probably be used without purification for N2O3 generation. Yields of the nitroalkene from anethole were not great (48%) but could probably be improved. For N2O3 generation, only use the acid + nitrite method; the Fe/HNO3 is a waste of time. I also suggest trying TsOH instead of H2SO4 to avoid forming nitrosylsulfuric acid.

https://erowid.org/library/books_online/pihkal/pihkal132.sht...
Quote:
A mixture of 50 g 1-(3-methoxy-4,5-methylenedioxyphenyl)-2-nitropropene and 26 g racemic a-methylbenzylamine was heated on the steam bath. The mixture gradually formed a clear solution with the steady evolution of nitroethane.


In fairness, I'm not sure what exactly you should substitute for alpha-methylbenzylamine, but beta-phenethylamine is OTC.

Anethole looks like a big molecule, but you're not wasting that much -- the MW is 148, vs. nitroethane at 75. So the theoretical w/w yield is about 50%.

[Edited on 13-2-2019 by clearly_not_atara]