Nitroalkane Preparation FAQ

[malvaxman]

From Nitroalkane Preparation FAQ
by Rhodium

Preparation of Sodium Ethyl Sulfate

"Two moles of absolute ethanol (92 grams) is slowly dripped into a beaker containing one mole of 20% Oleum (H2SO4 containing 20% SO3), adjusting the rate so that the temperature is maintained at 45°C. When all the ethanol is added, the solution is neutralized with anhydrous sodium carbonate (Na2CO3), care being taken for the evolution of carbon dioxide. Yield 85% of theory."

"Nitroethan from Sodium Ethyl Sulfate [4]

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 nitromethane is then re-distilled, collecting the fraction between 114-116°C. Yield 46% of theory."

Full text:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html

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Is there any way to make Oleum from normal H2SO4?

/thank you for your help..

[Antoncho]

Is there any way to make Oleum from normal H2SO4?

There is no such way.

The only practical method of SO3 produc'n is heating NaHSO4 - 1st it splits off water, giving Na2S2O7, then at ~300 C it gives off SO3. Which you can bubble into conc. H2SO4.

However, you gotta bee really crazy to do that, especially for making smth as simple as NaEtSO4. I suggest you UTFSE ("ArOR, the alternatives to...." in Novel D. and "Kitchen nitroalkane success" in Chem. D.) - it explains pretty much everything. You don't need pure NaEtSO4 for that.

See also "hydrogen ethyl sulfate" thread by Foxy2.

Antoncho

[uemura]

Hi fellow bees,

Is there any way to make Oleum from normal H2SO4?

Would it bee possible to add stochiometric amounts of P2O5 into H2SO4, warm until the P2O5 dissolves (*) and just use the Oleum/HPO3 mixture for further processing. Does the HPO3 interfere?

Carpe Diem
(*) Up this this point, a small experiment showed the P2O5 dissolves and sucks away some water from the H2SO4.