There's an article on Rhodium's site (here:https://www.thevespiary.org/rhodium/Rhodium/chemistry/alcohol2nitro.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/alcohol2nitro.html)
) that suggests preparation of nitroalkanes by just mixing an alcohol, acetic acid and sodium nitrite in DCM and adding conc. HCl.
This sounds too easy to be true. Does it work? Anyone ever try this?
Hansje high in proteine and fibre!
Yes, SWIM tried the rxn you mention - unsuccessfully. There are some obvious, even from theoretical standpoint, obstacles in this method - however, it can and should bee optimized (SWIM couldn't do that, for purely financial reasons).
His practical xperiences, as well as theoretical musings, can bee found in Post 199007 (https://www.thevespiary.org/talk/index.php?topic=11508.msg19900700#msg19900700)
(Antoncho: "Re: nitro mechanism", Novel Discourse) and downwards from it in that thread.
Hansje - If you' re going to try doing it the way i suggested (w/some drying agent to remove formed water), it would bee most wonderful and potentially revolutionary experiment! ;)
Antoncho
Oh, the reason for this method not being patented is very, IMHO, simple: it's very unpractical from economic standpoint. Nitroalkanes are commonly industrially made by exactly that gas-phase nitration method, which is a hundred times cheaper.
Now, i wonder, if someone will ever give a proper try to that EtCl + NaNO2 in boiling water thing (patented for production of nitromethane - see Post 200843 (https://www.thevespiary.org/talk/index.php?topic=11277.msg20084300#msg20084300)
(Antoncho: "Nitroalkanes from Me/EtCl and aq. NaNO2!", Novel Discourse)) - SWIM didn't succeed w/it - but obviously, beecause he lacked a proper foaming agent. The rxn occurs in gas-liquid surface. I would also bet that some PTC would bee of invaluable help for it.
It is somewhat complicated in terms of apparatus, but a technically inclined bee like Half-a-Pint, e.g., can certainly manage it with ease ;)
Anyway, sounds way better to me than vapour-phase nitration ::) ::) :)
Antoncho
OK, Hansje. Let's just make sure, this advance is accompanied by a similar advance in backyard industrial caution. Red oxides of nitrogen are not just scary, they really hurt you.
Antoncho:
"if someone will ever give a proper try to that EtCl + NaNO2 in boiling water Post 200843 (https://www.thevespiary.org/talk/index.php?topic=11277.msg20084300#msg20084300)
(Antoncho: "Nitroalkanes from Me/EtCl and aq. NaNO2!", Novel Discourse)"
Wonder if diethyl sulfate or yr. sodium ethyl sulfate wd. function alternatively in this rxn. For that matter, would diethyl sulfate work in the room temperature rxn in DMSO? Think we're onto an easier path to diethyl sulfate, bubbling SO2 through CuCl2 sol'n in ethanol. See Post 278794 (https://www.thevespiary.org/talk/index.php?topic=7501.msg27879400#msg27879400)
(halfapint: "Re: Dimethyl/Diethyl Sulfate", Chemistry Discourse). Sodium ethyl sulfate, I'm hearing, is sleepy simple: neutralize sulfuric acid in excess ethanol with Na carbonate ("pH-Up") then strip off the ethanol. Ethyl chloride seems cheap and easy, but as a gas, once through and it's gone. Has let's say a low residence time in boiling water. In general, I consider gases as wasteful reagents.
"a proper foaming agent. The rxn occurs in gas-liquid surface. I would also bet that some PTC would bee of invaluable help for it."
Yeah. Trouble is, foam automatically means foaming space. That already means "backyard industrial advance" scale, not "fold up your lab and stick it back under the cabinet" scale. A general-purpose bubble builder is detergent and glycerine, but I don't think we want foam quite that persistent, so we should try dishwashing detergent and ethylene glycol (antifreeze) here.
Why do I visualize a pot of broken glass for this rxn? OK, dig -- the rxn takes place in the liquid-gas interface, right? The film of fluid which runs down a glass surface, has a maximal exposure to surrounding gas, like the surface of a bubble does. Foam seems inconvenient to handle, hard to control, but boiling nitrite solution in a pot full of glass shards (inert packing material: Raschig rings, glass wool, silica gel beads, potsherds, rocks) in a tall pot without the foam, I could feel more comfortable with gassing from alcohol boiled with HCl. Perhaps there's a middle ground, with just a little bit of foam in lots of rocks.
"It is somewhat complicated in terms of apparatus, but a technically inclined bee like Half-a-Pint, e.g., can certainly manage it with ease"
Gotta get a workshop. Got to have a dedicated space to work. Tired of breaking glass from lack of elbow room. Don't like building submarine-locker size apparatus.
a half a pints a half a pound a half a world a half a round
Sidearm n. Flask neck tube.
E-Z Nitroethane proposal.
https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitroalkane.html)
sez:
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.
Here's a Boiling Water Reflux version.
(1) Alcohol and Sulfuric prep of ethyl hydrogen sulfate: drop sulfuric acid gradually into an excess of cool alcohol and stir.
(2) Add portionwise enough sodium carbonate to make it basic. Hint: until sodium bicarbonate you add as indicator quits fizzing, then one more portion.
(3) Sodium Ethyl Sulfate prep: Boil off the alcohol, until the sodium ethyl sulfate and its slight admixture of sodium carbonate are dry.
(4) Nitroethane production: Add (overall excess) sodium nitrite solution in water, then reflux into a packed column. 'Bout that long.
(5) Distill off water, optionally under reduced pressure.
(6) Fractionally distill off nitroethane, optionally under reduced pressure.
a half a pints a half a pound a half a world a half a round
Sidearm n. Flask neck tube.