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)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.kornblum.dmf.pdf)
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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)
(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)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-1.pdf)
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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)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-2.pdf)
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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)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/nitroethane.propylnitrate-3.pdf)
Some time ago I tried making EtNO2 via the EtBr/NaNO2/DMSO route on two occaisions, Only the EtBr was prepared by myself which was distilled before use, and damn me the entire bloody thing set to a solid crystalline mass just before all the EtBr was added. None of the desired product was isolated, complete and utter failure. The DMSO appeared to have been consumed by this reaction. I never worked out went wrong.
I had very similar results... I also tried this route twice. The first time I had results very similar to yours, though I produced an incredibly foul smelling product in the course of things.. I'd bet it was a nasty sulfur compound by the horrific stench of it - that smell stuck around the room I tried that reaction in for quite a while as well :( I tried it again some time later in the presence of catechol. Didn't get the unworkable solid, and no horrific smell, but out of the funky brown stew resulting from the attempt came no nitroethane.
Next time I try to make nitroethane damnit, I'm going to give the destructive distillation of 2-chloropropionic acid in the presence of sodium nitrite a try..
-SpicyBrown
The procedure in Org. Synth., Coll. Vol. 4, 724 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0724)
(http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0724) was followed with 2 mol EtBr and 2 mol AgNO2. Distillation of the reaction mixture at atmospheric pressure gave ether contamined with EtONO and NOx as a forerun and then 75-80 % yield of EtNO2 boiling at 108-112 C.
Ether containing EtONO was attempted to purify by shaking with dilute HCl and water. Drying with NaOH and then with metallic Na led to reduction of leftovers of nitrogen impurities to ammonia, which was precipitated with concd H2SO4. Ether was after drying with NaOH and then with Na suitable for using in the reaction.
I assume that low-boiling petroleum ether could be good substute for ether, but I didn't try it.
The AgBr precipitate*, which was filtered from the reaction mixture, was allowed to dry in air and suspended in 1000 ml hot water. Diluted H2SO4 was added to destroy nonreacted AgNO2 and NOx were allowed to escape. The addition of H2SO4 was repeated at times to maintain the solution acidic. To slightly acidic hot solution was then added zinc wire** of diameter 3-5 mm. It is advantageous to use this wire as a stirring rod. Immediately after the wire reached the AgBr precipitate, the reduction of black Ag occured at the point of contact. After several hours the reaction was finished; it was necessary to keep solution acidic by occasional addition of H2SO4. Reduced Ag formed characteristic light gray precipitate, which was dried in air.
This Ag was dissoved in cca 20 % HNO3, solution was shortly boiled to remove NOx and excess acid was carefully neutralized with diluted NaOH. The neutral solution was suitable for production of next batch of AgNO2 (see Org. Synth. procedure).
* The mother liquor and washing liquors from AgNO2 preparation were collected and excess of NaCl solution was added to them. Precipitated AgCl was then added to AgBr, so the overall lost of Ag at this 2 molar scale was lower than 1 g.
** Zinc wire was used in excess. It was found to be much better than zinc powder. If slight contamination of Ag with carbon doesn't matter, the steel wire could be also used, but I didn't try it.
alkane + HNO3 is how the lower aliphatic nitroalkanes are made in industry. this is not suited for most people but if you like to build things...and it doesn't seem that there are simpler alternatives using these alkanes.
you get a mixture of nitroalkanes with ethane and the ratio of products is highly dependent on conditions. high temp vapor-phase is generally used, probably multi-pass as well, i don't remember. see Patent US1967667 (http://l2.espacenet.com/dips/viewer?PN=US1967667&CY=gb&LG=en&DB=EPD)
for why a more convenient method isn't around, AFAIK. you could probably find more with a "referenced by" search of the patent databases, this is the classic patent on this.
ten years ago i read a great Ind. Eng. Chem. article full of yields of various nitroalkanes under various conditions from methane to butane, in neat tables. a definitive article with much text as well. and came away thinking...silver nitrite and ethyl iodide. but i dont remember which article and of course you ask on a day on which all libraries are closed in the usa!
the inventor of vapor phase nitration, Hass, has a lot of Ind. Eng. Chem. articles, and some in JOC and JACS. his name got a lot of hits in TFSE, btw. so i don't know which of the following is best for the industrious, able bee, if any. all are by Hass, industrial methods not very well suited for most but you get the idea, and in Ind. Eng. Chem:
nitration of ethane: 32, 427 (1940)
various: 41, 2266 (1949), 33, 1138 (1941), 38, 251 (1946)
review: 39, 817 (1947)
I thought this post might be of some interest to readers of this thread......java
.................as read with full article in Post 538899 (missing)
(Lego: "TCICA: Decarboxylation of amino acids to nitriles", Novel Discourse)
Conversion of alpha-Amino Acids into Nitriles by Oxidative Decarboxylation with Trichloroisocyanuric Acid
Gene A. Hiegel, Justin C. Lewis, and Jason W. Bae
Synth. Comm., 2004, 34(19), 3449-3453
DOI:
:10.1081/SCC-200030958 (http://dx.doi.org/%3A10.1081/SCC%2D200030958)
Abstract: Trichloroisocyanuric acid oxidation of alpha-amino acids in water or methanol in the presence of pyridine produces nitriles with one less carbon in good yields and of high purity.
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000474617-Untitled-1_copy.jpg)