| Pages:
1
2 |
Elrik
Hazard to Self
Posts: 52
Registered: 1-9-2018
Member Is Offline
|
|
I'll be needing some dioxane next year and so have been looking for uses for the byproduct acetaldehyde. I've already got enough nitroethane, but this
is one potential route people could use.
• make useful dioxane and also save the acetaldehyde. Adding a solvent that wont sulfonate, like heptane, to the ethylene glycol/sulfuric acid may
increase acetaldehyde yield at the cost of dioxane.
• buy hydroxylamine or make it from nitrite and bisulfite or metabisulfite, use it to make acetaldehyde aldoxime
• dissolve acetaldehyde aldoxime in glacial acetic acid, add perborate, and gently heat for a few hours to oxidize it to nitroethane
• add some water, distill over the nitroethane-water azeotrope, salt it, wash the organic layer with saturated salt water, dry with calcium chloride
and distill the nitroethane.
|
|
|
chemplayer...
Hazard to Others
Posts: 191
Registered: 25-4-2016
Location: Away from the secret island
Member Is Offline
Mood: No Mood
|
|
For ethyl iodide without red P you have two choices:
1. Use ethanol, KI and phosphoric acid together.
2. Use aluminium foil in place of the red P (limited yield).
We've done both and they both work (iodine is fairly easy to recycle from the reaction mixtures). Be prepared for patience and a slow reaction in both
cases however with many hours of distillation of the reaction mixture to get a reasonable yield.
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Based on my prior research (see extract below for references on the commercial metallurical application on the cited technique), I would speculate
that one may be able to improve the aluminum foil approach to ethyl iodide by imbuing the surface of the added Al with the hydrogen atom radical
(where the •H is created from a prior reaction of say NaOH on Al). Further, apply sunlight to dry KI resting in EtOH, as it is photosensitive. My
take on some of the possible chemistry:
•H + EtOH --> H2 (g) + EtO• (see Buxton's related Eq (6) at https://pdfs.semanticscholar.org/d696/b35956e38351dd2eae6706... )
The above reaction also advantageously reduces the formation of problematic water, however, it is a much slower reaction than occurrs with the
hydroxyl radical.
I- + hv --> •I + e- (see Buxton Eq (17))
•H + •I = HI
HI + EtOH = H2O + EtOI
EtO• + •I = EtOI
Problematic reactions that could reduce yield:
EtOI + •H = EtO• + HI
EtOI + e- = EtO• + I-
2 Al + 6 EtOH --> 2 Al(EtO)3 + 3 H2 (g)
Al + 3 •H +3 EtOH --> Al(EtO)3 + 3 H2 (g) (see below)
In the presence of water and any created Al(EtO)3 :
2 Al(EtO)3 + 3 H2O = 2 Al(OH)3 + 3 EtOH
HI (aq) = H+ + I-
H+ + e- = •H
H2O + e- = •H + OH- (slow)
Al + 3 OH- --> Al(OH)3 + 3 e-
.....
Prior thread citation (link: http://www.sciencemadness.org/talk/viewthread.php?tid=97948#... ):
Quote: Originally posted by AJKOER  | Here is a suggested path to make aluminium isoproxide without using any mercury, basically follow a cited path (see Wikipedia, https://en.wikipedia.org/wiki/Aluminium_isopropoxide#Referen... ):
2 Al + 6 iPrOH → 2 Al(O-i-Pr)3 + 3 H2 (g)
However, I would suggest to first treat the Al metal with either NaOH and HCl. As I discussed previously (see my comments on •H at http://www.sciencemadness.org/talk/viewthread.php?tid=40137#... ), this may imbue the surface of the Al with the hydrogen atom radical (•H).
Target reaction to possibly accelerate product formation:
•H + iPrOH ---> •O-i-Pr + H2 (g) (see related Eq (6) at Buxton work at https://pdfs.semanticscholar.org/d696/b35956e38351dd2eae6706... )
Al --> Al3+ + 3 e-
•O-i-Pr + e- --> O-i-Pr-
Net:
Al + 3 •H +3 iPrOH --> Al(O-i-P)3 + 3 H2 (g)
I would expect the above reaction system to have a higher reaction rate and, upon collecting evolved hydrogen over water, twice the volume of
generated H2 per mole of consumed Aluminum compared to the Wikipedia cited equation.
[Edited on 27-10-2018 by AJKOER] |
|
|
|
VSEPR_VOID
National Hazard
Posts: 719
Registered: 1-9-2017
Member Is Offline
Mood: Fullerenes
|
|
| Quote: Originally posted by chemplayer... | For ethyl iodide without red P you have two choices:
1. Use ethanol, KI and phosphoric acid together.
2. Use aluminium foil in place of the red P (limited yield).
We've done both and they both work (iodine is fairly easy to recycle from the reaction mixtures). Be prepared for patience and a slow reaction in both
cases however with many hours of distillation of the reaction mixture to get a reasonable yield. |
I tried making ISP iodide by that method and failed. I used I2, Al, and the anhydrous alcohol.
Within cells interlinked
Within cells interlinked
Within cells interlinked
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
No HI no iodide.
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
Al + I2 will generate some HI. After all, anhydrous AlI3 + H2O certainly does. The problem is that you get crap like AlOI and AlI2OH that
interferes with the reaction and prevents a lot of the iodine from reacting.
You can do this reaction with phosphoric acid and KI, distilling out the alkyl iodide as it forms. That certainly seems a lot cleaner than screwing
around with amphoteric aluminum compounds.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
*drums fingers*
|
|
|
nimgoldman
Hazard to Others
Posts: 303
Registered: 11-6-2018
Member Is Offline
|
|
| Quote: |
For the silver is not a problem, but the ethyl iodide is. In the US red phosphorus is hard to get as the DEA will have a fit.
Can it be made without red phosphorus. |
One way around might be first producing HI using phosphoric acid and KI, then reacting HI with ethanol, yielding ethyl iodide.
However, ethyl bromide might be usable too, only requiring much longer reaction time.
My attempts for Victor-Meyer reaction failed with both EtBr and EtI, producing only very little nitroethane (like 1-2 milliliters instead of 15-30 mL
expected). I am still looking up why that failed...
|
|
|
Jackson
Hazard to Others
Posts: 189
Registered: 22-5-2018
Location: U S of A
Member Is Offline
Mood:  Happy about new glassware
|
|
I know this has probably been discussed before, and probably isn’t possible, but could nitroalkanes be made by the oxidation of the alkylamine using
pottasium permanganate? For example, could nitroethane be made from ethylamine and potassium permanganate? Sounds like probably a no but if it is
possible then that’s pretty cool and potentially useful.
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
| Quote: Originally posted by Jackson | | I know this has probably been discussed before, and probably isn’t possible, but could nitroalkanes be made by the oxidation of the alkylamine using
pottasium permanganate? For example, could nitroethane be made from ethylamine and potassium permanganate? Sounds like probably a no but if it is
possible then that’s pretty cool and potentially useful. |
You would have known if it was possible.
There are some less OTC methods though. They work for aryl-amines though
https://www.organic-chemistry.org/synthesis/N2O/nitrocompoun...
[Edited on 13-2-2019 by Tsjerk]
|
|
|
clearly_not_atara
International Hazard
Posts: 2692
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
So if you can deal with NOx gases, there's a pretty simple method from anise oil (anethole) which is OTC:
anethole + N2O3 -> anethole pseudonitrosite dimer + KOH -> 2-nitroanethole
https://erowid.org/archive/rhodium/chemistry/pseudonitrosite...
Incidentally, I'd guess that crude nitrite made by pyrolysis of nitrates can probably be used without purification for N2O3 generation. Yields of the
nitroalkene from anethole were not great (48%) but could probably be improved. For N2O3 generation, only use the acid + nitrite method; the Fe/HNO3 is
a waste of time. I also suggest trying TsOH instead of H2SO4 to avoid forming nitrosylsulfuric acid.
https://erowid.org/library/books_online/pihkal/pihkal132.sht...
| Quote: | | A mixture of 50 g 1-(3-methoxy-4,5-methylenedioxyphenyl)-2-nitropropene and 26 g racemic a-methylbenzylamine was heated on the steam bath. The mixture
gradually formed a clear solution with the steady evolution of nitroethane. |
In fairness, I'm not sure what exactly you should substitute for alpha-methylbenzylamine, but beta-phenethylamine is OTC.
Anethole looks like a big molecule, but you're not wasting that much -- the MW is 148, vs. nitroethane at 75. So the theoretical w/w yield is about
50%.
[Edited on 13-2-2019 by clearly_not_atara]
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
