The Hive > Methods Discourse

question about Nitroethane-synths

(1/6) > >>

evil_emma:
After reading a whole lot in here about the synthesis of Nitroethan, I still have a couple of questions that I need you bees to help me out with  :) .

The synth wich interests me the most (both due to the yield & the chems used) is #3 in Aurelius compilation. It uses sodium nitrit & ehtyl bromide in DMSO. The reading is great but has anyone here any experience with this synth? I read in Total Synthesis II that this synth doesn´t work out without using Phloroglucinol as nitrite scavenger? Does it, or does it not? If it has to be used, can urea (as said in Aurelius #3) be used as nitrite scavenger as well as Phloroglucinol? Urea is alot easier to obtain than Phloroglucionol.

Aurelius #3 tells us urea can be used when using DMF as solvent, but I guess that if it CAN be used -it would work out i DMSO as well? (DMF not available where swim lives).

Also, has anyone tried performing this in ethylene glycol instead of DMSO/DMF? This synth uses ALOT of solvent, so it would be cheaper to be able to use it.

And what is really the appropriate volume of solvent (DMSO)? Aurelius #3 uses 600ml DMSO/36,5g ethylbromide/36g sodium nitrite & Ritter uses almost exactly the same amount of ethyl bromide/sodium nitrite, but only 250ml DMSO (+52g. Phloroglucinol). Using 600 ml DMSO (wich by my knowledge is not possible to recycle out of this solution) is going to be VERY expensive when synthesising liters of Nitroethane! So what is really the minimum amount that could be used?

I would really appreciate all help I can get on this one!

Rhodium:
It seems like you need to read the original literature on this topic. The limiting factor is the solubility of sodium nitrite in the solvent used.

A New Method for the Synthesis of Aliphatic Nitro Compounds (in DMF)
N.Kornblum, H.O. Larson, R.K. Blackwood, D.D. Mooberry, E.P. Oliveto, G.E. Graham
J. Am. Chem. Soc. 78, 1497-1501 (1956) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.kornblum.dmf.pdf)
____ ___ __ _

Synthesis of Aliphatic Nitro Compounds (in DMSO)
Nathan Kornblum, Jack Powers
J. Org. Chem. 22, 455-456 (1957) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.kornblum.dmso.pdf)


Bonus: Nitroethane from propyl nitrate (the goods is in part III, but it references the other two).

The Thermal Decomposition of Nitrate Esters. I. Ethyl Nitrate
Joseph B. Levy
J. Am. Chem. Soc. 76, 3254-3257 (1954) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-1.pdf)
____ ___ __ _

The Thermal Decomposition of Nitrate Esters. II. The Effect of Additives on the Thermal Decomposition of Ethyl Nitrate
Joseph B. Levy
J. Am. Chem. Soc. 76, 3790-3793 (1954) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-2.pdf)
____ ___ __ _

The Thermal Decomposition of Nitrate Esters. III. n-Propyl Nitrate
Joseph B. Levy, Frank J. Adrian
J. Am. Chem. Soc. 77, 2015-2016 (1955) (https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-3.pdf)

Daphuk_up:
SWID apologizes for bumbing this old thread, but he has a few questions and comments he would like to put forth.

First, although SWID is far from a competant chemist, he examined the mechanistics and came to understand how it was actually working.  Then he played with Isopropyl Nitrate, and decided that it would probably produce nitromethane or something else entirely.  He saw one possible route, but doesn't know enough about radical formation and reaction to postulate on the probability.

SWID is thinking that all that is moot anyways, since this is actually pretty unpractical for any sort of clandestine nitroethane production.  He thinks this way because of the low pressures they use...at first he thought they meant 54.2mm above atmospheric.  At 54.2mm total pressure, a 1L container will only be holding 3mmol (according to the ideal gas law).  50% conversion would leave a whopping ~.113g of nitroethane.  Of course, SWID realizes that these posts aren't necessarily intended to cater to the OTC types, but SWID is saying the article is more interesting for the mechanistics than any sort of practical application.

Just for the hell of it, SWID is going to guess that the main intermediaries from isopropyl nitrate, following the formation of NO2 and the CH3CH2(O*)CH3 radical is acetaldehyde and methyl radical.  The methyl radical could then combine with the NO2 to form nitromethane.

SWID also finds it interesting that he can find no mention of the final pressure in the container after "decomposition".  The term is misleading to those (such as SWID) who are still newbees.  What they are really doing is heating the propyl nitrate till it explodes...except at very low pressures so the reaction is still manageable.  "Explosives Research Department, U.S. Naval Ordinance Lab" pretty much says it all.

SWID had high hopes for this...nitroethane with using the ever-so-precious sodium nitrite. :(

Antibody2:
ever-so-precious sodium nitrite.
25kgs bags of sodium nitrite can be purchased for $50.

Disciple:
Does anyone have any experience or literature with the ozone oxidation of ethylamine. It has been hinted at but...

Navigation

[0] Message Index

[#] Next page