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epck
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I've heard this can be done to produce nitroethane, the following is from the rhodium nitorethane FAQ:
"Method 14: Vapor Phase nitration of propane.
The propane is bubbled through nitric acid heated to 108°C and lead into a reactor at 420°C.the product is then condensed and fractionated.(26%
nitroethane formed)
Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344.
JOC, Vol 17, pg 906-944.
Method 15: Vapor Phase nitration of ethane.
Same as propane but at least 80% yields.
Industrial and Engineering Chemistry, Vol 28, Mar, 1936. Pg 339-344.
JOC, Vol 17, pg 906-944. "
I would assume, possibly incorrectly, that the same reaction would hold true for methane. However I have not tried either reaction.
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chemoleo
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Another thing I wondered, would diazotation be possible?
I.e. from methylamine, convert to the azo form and use NaNO2 to get nitromethane.
Any ideas? Or does diazotation and substitution only work with a select range of ions? (Cl, CN, etc)
Never Stop to Begin, and Never Begin to Stop...
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The_Davster
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I have not seen any mention anywhere regarding substituting a diazo group with a nitro before unfortuantly.
Well today I came across a mention that the vapour phase nitration of methane with nitric acid occurs around 460C, not that easy of a temperature, but
not completly out of reach either. Also, vapour phase nitration of alkanes higher than methane will always produce nitromethane as a byproduct, but
by the time you reach either propane or butane the percentage of NM formed is only around 2%. Seeing as these are radical reactions with nitration of
butane, for example, you would get a mix of nitrobutane, nitropropane, nitroethane, and nitromethane.
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sparkgap
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"Another thing I wondered, would diazotization be possible?"
It's possible, but gnarly. The resulting methyldiazonium ion would be really keen to decompose into the methyl carbocation and nitrogen, so that would
present you with a possible explosion risk.
Otherwise, the methyl carbocation would take on any nucleophile within reach, so I'd think this diazotization shouldn't be done in aqueous medium
unless you want methanol also...
sparky (~_~)
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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chemoleo
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Another synthesis route
I'm not sure whether this has been mentioned elsewhere, if so let me know.
Apparently, nitromethane can also be made by warming sodium chloroacetic acid in an aqueous solution with a stoichiometric amount of sodium nitrite
NaNO2.
The resultant MeNO2 is separated by steam distillation (bp 120 deg C).
The reaction was first described by Kolbe.
However, the yield is 35-38%
However, if chloro-acetic acid can be made easily, I'd probably go for that reaction.... seems most straightforward, despite the bad yield!
I tried to search this forum on CAA, but only found this thread. It appears Polverone had a go at it with trichloroethylene and H2SO4 reflux?
Is direct chlorination of HAc possible?
Edit: Silly me, it's on OrgSyn!
Detailed conditions, that's all we need! NOw there remains an easy chloroacetic acid prep!
PS Sparkgap/rogue, you are indeed correct. I did some checking... and it's definitely not suitable.
[Edited on 7-12-2005 by chemoleo]
Never Stop to Begin, and Never Begin to Stop...
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Chris The Great
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I remember reading a journal posted here about this reaction also decomposing the nitromethane, hence the low yield. It then went on for a higher
yield reaction. Of course, I was busy at the time, didn't read it, and forgot about it until now. But if anyone remembers that article...
Chloroacetic acid is pretty easy if you have phosphorus. Basically, Cl2 + glacial acetic acid with P catalyst. Sulfur apparently works but poorly...
No other details, but Vogel has detailed procedures for both these reactions.
It also mentions adding a NO2 group by diazotation, using NO2BF4. It mentions a possible explosion risk... I doubt it would be stable to react in
this case, in Vogel it was used as an example for preparing pure isomers of aromatic compounds (for example pure 1,2 dinitrobenzene).
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garage chemist
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Chloroacetic acid synthesis can be found here:
http://designer-drugs.com/pte/12.162.180.114/dcd/chemistry/c...
I think I'll try it some day. As the light source I'll use a 500 watt halogen light, with the front glass removed (normally filters out UV).
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kclo4
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Well i just read that chloropicrin reacts with NaOH and water to form sodium nitroacetate and sodium chloride. Here:
http://www.erowid.org/archive/rhodium/chemistry/nitroalkane....
it says the sodium nitroacetate is very unstable and reacts with water to make sodium bicarbonate and nitromethane! so making nitromethane should be
easy, after you make the solution you could add a lot of salt to make the nitromethane come out of solution and float to the top, then it can be taken
out with a sepetory funnel. I think this method would have good yields and maybe a good route to go with if one needs nitromethane. dose anyone have a
comment on making nitromethane this way?
I don't know if this is any help but what could it hurt to mention?
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Fulcanelli
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I made nitromethane sucessfull by this way:
- Mix 100g chloroacetic acid & 200ml H2O
- Neutralize the solution with Na2CO3 (slowly, there will be a lot of CO2)
- Mix with a (freshly prepared) soln. of 70g NaNO2 (sodium nitrite) in 120ml H2O
- Distill (carefull, slightly exothermic reaction)
The distillate will be mainly water containing the MeNO2 (unsolouble). If no more MeNO2 comes over, the reaction is finished.
- Separate the phases of the distillate
- Saturate the aqueous layer with NaCl and distill off some more MeNO2.
- Extract the distillates with DCM
- Evaporate the DCM and dry the MeNO2 with CaCl2
Yield will be 50-60ml MeNO2. Sounds not so much, but if you need it for 2C-H production it's quite a lot...
This works too for Nitroethane, but the yields are low and the reaction more exothermic, so be careful if you try it.
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bio2
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........Could this reaction work and if not why not?
CH4OH + NH4Cl = CH3NH2 + HCl + H2O ....
Assuming that you meant MeOH + NH3.HCl
then yes this method will work at 300 C using
Ferric or zinc chloride as catalyst/dehydrator in a sealed vessel.
The product is the amine hydrochloride.
METHYL AMINES FROM METHYL ALCOHOL AND
AMMONIUM CHLORIDE.’
BY W. D. TURNEK AND A. M. HOWAI,D.
Received September 30, 1920.
US2085785 is a patent using the same method.
On another note, regarding nitroalkane synthesis from
Na alkyl sulphates and NaNO2. This can be done in aqueous solution and yields are even better than the dry procedure if
properly done!
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The_Davster
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| Quote: | Originally posted by chemoleo
NOw there remains an easy chloroacetic acid prep!
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Hmm...Could chloroacetone undergo the haloform reaction with NaOCl leaving Na-chloroacetate?
I also wrote down from somewhere, although I have forgotten where, that:
Chloroacetone + NaNO2--> nitroacetone
nitroacetone +NaOH-> nitromethane.
And:
MeOH + p-toluene sulphonic acid ->methyl tosylate
methyl tosylate +NaNO2--> NM +sodium tosylate(I imagine can be recycled)
[Edited on 14-1-2006 by rogue chemist]
EDIT: On second thought, would chloroacetone react with NaOCl to make carbon tetrachloride? That would be interesting..
[Edited on 16-1-2006 by rogue chemist]
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The_Davster
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| Quote: | Originally posted by rogue chemist
Hmm...Could chloroacetone undergo the haloform reaction with NaOCl leaving Na-chloroacetate?
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Yes!
I added 1mL of chloroacetone to 25mL ~10% NaOCl. The solution instantly qent cloudy and after 30 min there was left a turbid upper layer and a very
small lower layer of what smelled like chloroform.
The chloroform was pipetted out and to the remaining solution was added 2g of NaNO2 in 40mL dH2O, this was transfered into a 500mL RBF with a
condenser on top and inside the condensor was a thermometer resting on the bottom of the flask( I don't have a 2 neck flask, I improvised). The temp
was slowly brought up to 80C with an alcohol burner and the colour of the mix turned yellow, at 85C bubbles of what is suposed to be CO2 was given
off, however upon removing the burner the reaction was not self sustaining like in the procedure on orgsyn. The mix was brought up to 100C over the
next 3 min and kept there for a couple of min untill the effervescence of CO2 had stopped and the rxn was simply boiling. Adding a drop of water into
the reaction produced a localized turbitity in the yellow, it looked as if something other than water and salts were in there (hopefully NM!).
The entire mix was allowed to cool to room temp and was poured into 75mL of ~10% NaOCl. I was testing for the presence of nitromethane by attempting
to make chloropicrin with it as chloropicrin has a much lower solubility than NM, about 10x less. No reaction was noticed(at least not like in
Haggis' vid Garage experiments with PS), other than the yellow colour slightly dissipating. I will smell tomorrow the mix, see if any
chloropicrin has formed, at a solubility of ~0.1g/100mL it is entirely possible that it dissolved completly. The scale I did this experiment at was
perhaps a bit small to get observable product, and the fact that I did not purify my chloroacetate or any other intermediates.
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Nicodem
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There is no theoretic base for such a reaction as the formation of sodium chloroacetate from chloroacetone and NaOCl. As the chloromethyl group's
hydrogens are the most acidic it would obviously get oxidized to -CCl3 and subsequently hydrolyzed to CHCl3 and the acetate.
Chloroacetone is also formed from acetone and NaOCl as an intermediate but its further chlorination to 1,1-di- and 1,1,1-trichloro-acetone is
considerably faster than its formation so it can not be isolated in chlorinations in basic media (such as NaOCl solutions are).
See the mechanism of the haloform reaction:
http://www.organic-chemistry.org/namedreactions/haloform-rea...
http://www.mhhe.com/physsci/chemistry/carey5e/Ch18/ch18-3-2b...
and many other web pages.
[Edited on 4-2-2006 by Nicodem]
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Chris The Great
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I guess you would need 1,3-dichloroacetone as opposed to just chloroacetone. Chlorination (Cl2) would first give chloroacetone, and then a mix
between 1,1 and 1,3 dichloroacetone. Add to NaClO and get chloroform and sodium chloracetate. All these compounds are toxic and irritants so great
ventilation would be a must I would think.
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The_Davster
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I stopped that attempt, after 24h no chloropicrin smell was detected, so that method is not workable.
I am currently trying in the garage chloroacetone+ NaNO2 --> nitroacetone and then nitroacetone +NaOH--> nitromethane.
I am just curious if these reactions work, theres no way I will scale up and use large ammounts of chloroacetone. Lets just say my prep of
chloroacetone was not so fun as I did not wash my glass after the rxn well enough with enough NaOH solution....
After I am done with my ~6g chloroacetone I will not likely make more.
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Nicodem
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Rogue chemist that is certainly a good idea to prepare nitroacetone this way. I have been thinking of that a while ago though in the context of
3-chlorobutan-2-one. However I never was so motivated to search for the literature and I’m not so sure the alpha-nitroketones hydrolyze so easily
(as for example the –CO-CX3 groups). Do you have any relevant references? I would be interested to hear what you found.
In case you might want to prepare some more chloracetone, the preparation as described in FR2633614 is very easy and I had no troubles in the
preparation of a 100g batch (only a couple of tears ). After the reaction you
just add a pinch of Na2CO3 to neutralize the catalytic amount of H2SO4 used, vacuum filter the cyanuric acid precipitate, wash it with some more
acetone, and then distill the filtrate in a fully closed system in a fume hood to get the recycled acetone and the higher boiling chloroacetone. It is
advisable to redistill the product to get it pure or alternatively use a distillation column. If it is not redistilled it gets dark in few weeks. The
yield after the redistillation was 75%.
The only point when you can get in troubles by exposing to chloroacetone is when you wash the glassware and if you don’t have a gas mask you better
dismantle and leave it outside for the irritating chloroacetone to evaporate. Also it is very important to cool the reaction in an ice bath as
described in the patent since it is quite exothermic and if it runs out of control to a boiling point, well then you are in really big troubles…
…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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The_Davster
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I am afraid my references to that reaction are rather obscured in my memory. It was one of those days at uni where I wander the chem section at the
library and grab random chem books and spend several hours pouring over then. From what I remember it was only mentioned in passing as "nitroacetone
can be cleaved by base to yield nitromethane and sodium acetate" This reaction was also mentioned in passing in an old thread on roguesci.
As for the synthesis of the nitroacetone I am not really basing it on much more than the synthesis mentioned in PATR 2700 which used silver nitrite
and iodoacetone in ether at 0 degrees C.
I made a solution of 1.2g NaNO2 in ~10mL dH2O and added 1mL of the chloroacetone to it. I have been swirling the testube every once and a while the
last day or so and both layers in the testtube have gone yellow(the chloroacetone was colourless to begin with). I know this set up is rather crude
with both reactant and product being insoluble in H2O, but I lack ether or DMSO, both of which I would like to try at some point.
I used the process off that french patent as well to make my chloroacetone, Orgie started a thread about it a couple of years ago or so. Everything
was fine till it came time to wash the glass, I just did not wash it with enough NaOH first...
My chloroacetone is about a month old now, it is still clear(I think there is some acetone contaminats though) after only one distillation.
"then distill the filtrate in a fully closed system in a fume hood" Lets just say without the fumehood I am not doing this again, especially a larger
batch. Outdoor experimenting is not an option currently....
[Edited on 7-2-2006 by rogue chemist]
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The_Davster
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After 2 weeks of the chloroacetone sitting in contact with a sodium nitrite solution in the garage, with the temp ranging from -30 to 10C outside, the
solution is yellow, and still 2 layers. Taking a small sample of a mix of the phases and adding it to a NaOH solution produced only a light pink
solution, unlike the bright cherry red of pure chloroacetone. So I figure it has nearly all reacted, a bit more time out there should do it I hope.
It will then hopefully be cleaved into nitromethane and nitromethane's presence will be tested by forming chloropicrin. Seeing as some acetone may be
in my chloroacetone, the formation of an insoluble liquid after the nitromethane is treated with bleach is not enough to determine whether what I have
is NM so I guess I will have to do the sniff test .
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Nicodem
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Nitroketone preparation and cleavage
I searched SciFinder and Beilstein and found some relevant references.
The nucleophylic substitution of alpha-haloketones with the nitrite is apparently possible, however I found no reference for alpha-chloroketones.
There were only a couple of references for alpha-bromoketones of which the most thorough and interesting is:
Munz, R.; Simchen, G.; Liebigs Ann. Chem. (1979) 628-638.
They use PTC conditions (NEt4NO2/CH2Cl2) and report several examples ranging from 3-bromobutan-2-one to 2-bromo-2-methyl-1-phenylpropan-1-one and
similar.
The other is a patent, US4035512 (also FR2274287 or DE2525512), where a substituted alpha-bromotetralone is used successfully to yield the appropriate alpha-nitroketone with NaNO2/DMF in presence of
fluoroglucinol (an alkyl nitrite scavenger).
For the cleavage of alpha-nitroketones to the appropriate acid and nitroalkane there are many references but almost exclusively for
2-nitrocycloalkanones. I have no idea why is it so. I would expect the cleavage would be possible with the acyclic nitroketones as well, but I only
found two references and both are archaic to say the least. In both these cases the ketone had additional groups that make the carbonyl more electro
deficient by electrowithdrawal. The first mentions the cleavage of alpha, para-dinitroacetophenone to nitromethane and the second of
Ph-CH(NO2)-CO-C(Ph)=C(Ph)-COOH to phenylnitromethane:
Thiele; Haeckel; Justus Liebigs Ann. Chem. 325 (1902) 10.
Cohn, G.; Chem. Ber.; 24 (1891) 3867.
The conditions for the ring opening of 2-nitrocycloalkanones seams quite simple and require a mildly basic aqueous solution of a base (diluted NaOH or
NaHCO3), nonaqueous conditions with KF as a base or acidic conditions (Amberlist resin in MeOH, yielding an ester instead of carboxylic acid). Two
papers are included in the attachment and there is also a patent on it, US4554387.
There is also a method to form alpha, alpha-dichloro-nitroalkanes with NaOCl directly from cyclic nitroketones. The paper is also included in the
attachment.
Attachment: nitroketones.zip (621kB)
This file has been downloaded 897 times
…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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The_Davster
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So I finally returned to my testtube of chloroacetone and nitrite....
It was a light yellow, with a white crystalline ppt on the bottom. There was no insoluble layer of chloroacetone left. I decanted the liquid in the
testtube into a solution of 0.6g NaOH in~20 mL H2O in a 50mL erlenmeyer. The solution instantly turned a rather dark yellow colour. No red therefore
no chloroacetone was left. The ppt from the testube was tested for chloride with silver nitrate, the ppt was just salt. So I know the nitrite did
react with chloroacetone leaving salt and *hopefully* nitroacetone. Hopefully my long rxn time at ambient temp(-30 to 20) did not cause loss of
nitroacetone.
In reterospect I should have used a stronger NaOH solution today to attepmt cleavage of the nitroacetone as nitroacetone likely will not cleave as
easily as trichloroacetone into chloroform. I will add more base in a few days if I think its necessary.
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The_Davster
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The 'nitroacetone' and NaOH has really darkened over the last few days. Yesterday I added half of it to 10% bleach, no separate layer formed and no
chloropicrin smell occured.
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guy
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Just wondering, why can't a regular nitration of methanol work?
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The_Davster
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Methyl nitrate =/= nitromethane
CH3ONO2 vs CH3NO2
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guy
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Wouldn't a nitration produce a nitro compound, not a nitrite ester? But anyways I found the answer, it is because aliphatic nitro compounds are
unstable in acidic environments.
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The_Davster
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| Quote: | Originally posted by guy
Wouldn't a nitration produce a nitro compound |
Not when technically it is the esterification of an alcohol with the nitronium ion. C-NO2 only occurs on aromatic rings by SeAr.
Aliphatic nitro compounds may be unstable in acidic medium, but that is not the reason you get C-ONO2 not C-NO2. What would NO2+ attack in a methanol
molecule? Carbon with its partial positive charge, or the big partial negative charge on the oxygen? In aromatic nitration either o and p or meta
have a partial negative charge, so the nitronium attacks there.
I am not sure I am explaining this coherently though.
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