Sciencemadness Discussion Board

Acetaldehyde synthesis

 Pages:  1  ..  3    5

Magpie - 12-3-2017 at 10:22



I had a suspicion that this was not a practical route to acetaldehyde. Usually practical routes can be readily found in published procedures.

Quote: Originally posted by byko3y  

I have no double the reaction is possible, but I have no idea how to perform it. The only thing I'm sure is that you can't get acetaldehyde by heating ethylene glycol in a dillute sulfuric acid.


I take it that you have tried it, then?

byko3y - 12-3-2017 at 11:34

I did not try exactly this one, but did something similar. Such additional entrainer as water leads to complex reactions of acetaldehyde with itself and ethylene glycol.

Waffles SS - 18-3-2017 at 09:32

US2042224 Process of converting a polyhydric alcohol to a carbonyl compound (Acetaldehyde from Ethylene glycol by Sulfuric acid at 150-175 C)

US2335238 By Zinc Chloride at -210-220 C

[Edited on 18-3-2017 by Waffles SS]

clearly_not_atara - 21-3-2017 at 13:50

Interesting. It seems that dilute sulfuric acid tends to favor the aldehyde where concentrated sulfuric acid may have given dioxane. However the requirement for pressurized reaction is an issue. Dilute sulfuric acid will lose water rapidly at 175 ºC. However it appears that you do get acetaldehyde by heating ethylene glycol in dilute sulfuric acid at 175 C under pressure while constantly replenishing water, although that may not be what byok3y envisioned when he said that.

The zinc chloride route is a vapor-phase reaction. That's kind of sad.

[Edited on 21-3-2017 by clearly_not_atara]

The jersey rebel - 23-4-2017 at 17:06

I've heard from weiming1998 that calcium hypochlorite and ethanol can be used as the high heat of the reaction distills the low boiling acetaldehyde without reacting further to make chloroform and calcium formate. Also according to nurdrage, acetylaldehyde does indeed form as a side product of dioxane synthesis but the yield is very low as dioxane is the preferred product

The jersey rebel - 23-4-2017 at 17:08

Quote: Originally posted by byko3y  
I did not try exactly this one, but did something similar. Such additional entrainer as water leads to complex reactions of acetaldehyde with itself and ethylene glycol.
That forms 1 methyl dioxylene by condensation of ethanediol and ethanal with the removal of water

JJay - 23-4-2017 at 18:04

I think you can drop ethanol into warm (I don't know how warm... maybe 70 C?) aqueous sulfuric acid / potassium dichromate and collect the distillate?

If that doesn't work (I don't know why it wouldn't), you can surely do an anhydrous oxidation of ethanol with chromyl chloride or PCC.

Oh, I just read that the OP doesn't have any sodium dichromate. That could make things tricky....

[Edited on 24-4-2017 by JJay]

clearly_not_atara - 25-4-2017 at 22:28

Also, OP's last post was 15 years ago...

I wonder if ethylsulfuric acid or ethylsulfate salts will react with DMSO similar to ethyl tosylate and benzyl iodide. High temperatures may be required.

JJay - 25-4-2017 at 23:39

Quote: Originally posted by clearly_not_atara  
Also, OP's last post was 15 years ago...

I wonder if ethylsulfuric acid or ethylsulfate salts will react with DMSO similar to ethyl tosylate and benzyl iodide. High temperatures may be required.


I don't know, but I have about a pound of ethylsulfate salts just sitting around collecting dust, and I've been meaning to pick up some DMSO... how high might these temperatures be?

clearly_not_atara - 26-4-2017 at 14:21

From Advanced Organic Chemistry, Fieser & Fieser, (c) 1961:

12.6 - Tosylate method - Kornblum found (1959) that primary saturated alcohols are converted into aldehydes in 60-85% yield by oxidation of the tosylates with dimethyl sulfoxide (DMSO) in presence of sodium bicarbonate at 150C. Benzylic tosylates are oxidized smoothly at 100C. The required esters can be produced from the halides; for example, by reaction of n-octyl iodide dissolved in acetonitrile with silver tosylate.

150 C is good for alkyl tosylates, so I would start there with sodium ethyl sulfate. It appears that basic conditions are preferable. Apparently I had swapped octyl for benzyl in my memory.

Acetaldehyde can ignite starting at 185 C. As such it is probably not advisable to perform the reaction much higher than 170 C.

[Edited on 26-4-2017 by clearly_not_atara]

JJay - 26-4-2017 at 15:24

Hmm... this is probably one for a fume hood....

Aqua-regia - 27-4-2017 at 08:54

When i was younger i produced once 0,2 liter acetaldehyde just for fun and curiosity with Limpricht-Piria reduction from 1856
In this case stochiometric Ca-acetate + Ca formate fine grinded and mixed very intimatelly. Poured it In a suitable metal retort or hemebuilt container and heated it very slow (avoid the carbonisation) till slight red colour ( cca 500 degrees.) appeared. If no more liquid ceased the reaction was done.

Well known, that formate are poverful reducing agent. By heating need calculating with byside reaction f. e. chain cracking too. The prep is not optimal, but rough materials are cheap and easy to get. The simplified reaction:

(CH3COO)2Ca + (HCOO)2Ca ——> 2 CH3CHO + 2CaCO3

Methode also good for other aldehyde from Ca- carboxilic salt

yield was 30%, the purification was over ammonia-aldehyd. It is a possible way to get higher yield grinding of materials with ball mill, and really controlled slow heating. Good luck for follower

Copper Oxide Catalyst for Ethanol Dehydrogenation

boilingstone - 26-5-2017 at 13:29

I think this is a good resource for this thread,

This paper outlines the preparation of copper oxide catalysts for the dehydrogenation of ethanol to acetaldehyde, and also gives data on each catalyst's activity over time and selectivity for acetaldehyde.

Some catalysts in this paper are claimed to produce high selectivities for acetaldehyde (~90%), and after 24hr runs, were easily regenerated to almost 100% of their original activity.

It's worth a look

Attachment: Dehydrogenation of Ethanol to Acetaldehyde.pdf (1.1MB)
This file has been downloaded 2022 times


clearly_not_atara - 19-7-2017 at 13:49

This paper outlines the use of N-chlorosuccinimide for the selective oxidation of alkoxides:

https://www.researchgate.net/profile/Adam_Lee6/publication/2...

R-CH2OH + B- >> R-CH2O- + BH

R-CH2O- + ClSu >> R-CH2OCl + Su-

R-CH2OCl + B- >> R-CH(OCl)- + BH

R-CH(OCl)- >> R-CHO + Cl-

It appears that you could use this to oxidize sodium ethoxide using TCCA which IIRC dissolves in ethanol. Sodium ethoxide can be prepared "OTC" using excess anhydrous sodium hydroxide (it is necessary to wear a face shield when working with anhydrous sodium hydroxide):

http://www.sciencemadness.org/talk/viewthread.php?tid=2656

Excess TCCA will probably result in the formation of chlorinated acetaldehydes, though, and it might be preferable to use a chlorinating reagent of constant strength (TCCA's first, second, and third chlorines have different activation energy for release).

[Edited on 19-7-2017 by clearly_not_atara]

byko3y - 20-7-2017 at 06:59

It is known that alkoxides are prune to oxidation by a regular air. However, I don't seem to find any reactions of N-chlorosuccinimide with alkali alkoxides, but I think the only reaction is reversible formation of alkyl hypochlorite, which is known to decompose into aldehyde and/or ester.

Assured Fish - 25-7-2017 at 21:52

Has anyone had any success by oxidizing ethanol using hot potassium dichromate H2SO4 solution?
I have about 600g of potassium dichromate on hand and im planning of trying it this coming weekend.
The question i have is with dilution, and whether or not its necessary. In the following prep they use quite high dilutions and they also add the ethanol chromate mixture to the hot acid slowly.
https://erowid.org/archive/rhodium/chemistry/acetaldehyde.ht...
I would try this however i only have potassium dichromate on hand and thus i would have serious solubility issues, using an enormous dilution seems counter productive and im sure it would result in loss of yield due to ethanal solvating in the mixture and not distilling out and also limiting the batch size.

However i recently discovered the following video where this guy simply mixes the dichromate sulfuric acid and ethanol and then distills it, he doesn't dilute the ethanol at all and only uses a 1m solution of H2SO4.

If this video is anything to go by then the chances of over oxidation are actually quite slim provided the conditions are kept mild, then mixing the components without caring too much about limiting the dichromate available seems unnecessary.

I might just try doing this wile using a slight excess of ethanol. I was just wondering if others had experimented with this before i go ahead.

Edit: shit i forgot to reference the video.
https://www.youtube.com/watch?v=i7Ai5JdPYaY

[Edited on 26-7-2017 by Assured Fish]

JJay - 25-7-2017 at 22:44

Overoxidation is almost certain to happen unless the acetaldehyde is removed as it forms. I don't think enormous dilution is necessary. I'm going to give this a try soon but plan to use sodium dichromate.

I think Tdep has made acetaldehyde with dichromates.

Assured Fish - 19-12-2017 at 20:43

Ok so i found a paper recently that claims its possible to oxidize primary and secondary alcohols using aqueous hydrogen peroxide with a catalytic amount of bismuth tribromide.

Courtesy of CJ: Attachment: lee2015.pdf (143kB)
This file has been downloaded 982 times

I think this could work rather well for the prep of acetaldehyde.
A fractional distillaion set up could be employed and the boiling flask charged with the aqueous H2O2 and ethanol and 10mol% of BiBr3.
The Boiling flask temp would have to be monitored but once 70*C is reached and the contents of the flask begin refluxing, then the acetaldehyde should be more than volatile enough to make its way past the fractionating column while the ethanol should remain mostly in the boiling flask provided the temp is controlled.

The distillate could then be reacted with ammonium hydroxide and filtered to acquire the ammonium acetaldehyde trimer.

I thought about this being done with just standard refluxing however the paper suggests that its still possible for over oxidation to take place if the reflux is continued for too long.

The paper seems to indicate that the reaction proceeds via the in situ generation of HBrO.

As for the BiBr3, from what ive read it can be conveniently prepared by the direct oxidation of bismuth with elemental bromine or by the reaction of hydrobromic acid with bismuth trioxide.

The only issue i see with BiBr3 is that according to the wiki the NFPA 704 code for health hazard is a 4. This seems rather odd as the same code is a 2 for the triiodide and trichloride.
I realize that NFPA 704 is not really a good indicator for toxicity and it can be rather inacurate at times but this still seems rather odd for a substance that is only corrosive.
Granted according to what ive read its very corrosive.
Probably safe to handle such a compound in a fume hood or with a respirator to be on the safe side.

https://en.wikipedia.org/wiki/Bismuth_tribromide
https://en.wikipedia.org/wiki/Bismuth_chloride
https://en.wikipedia.org/wiki/Bismuth(III)_iodide

http://www.nilechemicals.com/BISMUTH%20BROMIDEMSDSLAB.htm

Xrpdguy - 1-9-2018 at 08:48

Did anyone try to oxidase alcohol by using conc. Hydrogen-peroxide and Cu2+ salt as a catalyst like basic copper carbonate (malachite)?
I did.

Assured Fish - 29-9-2018 at 01:22


Quote:

Did anyone try to oxidase alcohol by using conc. Hydrogen-peroxide and Cu2+ salt as a catalyst like basic copper carbonate (malachite)? I did.

What was your result and precisely how did you do it?

Xrpdguy - 5-10-2018 at 07:39

Quote: Originally posted by Assured Fish  

Quote:

Did anyone try to oxidase alcohol by using conc. Hydrogen-peroxide and Cu2+ salt as a catalyst like basic copper carbonate (malachite)? I did.

What was your result and precisely how did you do it?


Actually that was one of my project where I determined the kinetic of that reaction. You can simply use one vial of 5 ml and add 1 ml of ethanol and 0.5ml of 30% hydrogen peroxide and few drops of concentrated solution of copper sulfate, copper chloride or copper chloride-trihydrate. Also you need to heat the mixture for about and minute or more and you can play with various temperatures from 50 to 200 degrees of Celsius.
I noticed that around 300 degrees Celsius the reaction became so fast and vigorous and the vial explode.
Be careful because of concentrated hydrogen peroxide. It can explode on lower temperature. As he said you can use instead of solution of copper salts malachite as a catalyst.
At the end of the reaction the main product is ethanol and I determined that by smell.

Assured Fish - 5-10-2018 at 23:53

Interesting, i suspect you mean to say "at the end of the reaction the main product is acetaldehyde"
Which you determined by smell.
I suppose its worth investigation, though i think we have all managed to make a small amount of acetaldehyde, its just very difficult to make a usable quantity.
I managed to isolate about a quarter tea spoon full of the aldehyde ammonium trimer, though the major product of the oxidation (potassium dichromate as oxidizer) was definitely acetic acid.
Its not easy to tell the difference between both the acid and the aldehyde by smell from what i gathered as both smells tend to mix together and somewhat trick the senses.
I haven't yet gotten the chance to smell pure acetaldehyde as its always got small amounts of acetic acid mixed into it.

Im not gonna say you didn't make acetaldehyde but im just skeptical that it was the major product, especially given your means of analysis.

Xrpdguy - 6-10-2018 at 09:43

Quote: Originally posted by Assured Fish  
Interesting, i suspect you mean to say "at the end of the reaction the main product is acetaldehyde"
Which you determined by smell.


Im not gonna say you didn't make acetaldehyde but im just skeptical that it was the major product, especially given your means of analysis.


I am made a mistake in typing sorry about that, you're right I wanted to say acetaldehyde instead of ethanol.
But acetaldehyde has a fruity odor and I determined only by smell and didnt notice an odor of anything other( like the rest of ethanol).
I agree that I need to do some other analyses but my project is still in a 'pilot step'.
There are many reactions for the termination of aldehydes like Tolen's test.

draculic acid69 - 27-3-2019 at 05:37

In regards to the h2so4 and ethylene glycol method one should probably just follow the dioxane method and attach a hose to the vacuum takeoff and bubble the what should be gaseous acetyldehyde through some nh3 to collect it as the adduct and work it up from there.dioxane is certainly the main rxn product of that rxn and ethanal is just a small side product.maybe nh3 could be placed in the receiver to catch it as it comes over from the rxn pot as the adduct.nh3 won't react with dioxane will it? Maybe it will stop the rxn of ethanal,water and glycol as it will be neutralized quickly and not have time to react.

[Edited on 27-3-2019 by draculic acid69]

draculic acid69 - 27-3-2019 at 05:46

Calcium formate and calcium acetate destructively distilled seems to be the best easiest way to go if you need some for a rxn.can easily be scaled up to create larger amounts quickly.

Ubya - 27-3-2019 at 06:11

Quote: Originally posted by draculic acid69  
Calcium formate and calcium acetate destructively distilled seems to be the best easiest way to go if you need some for a rxn.can easily be scaled up to create larger amounts quickly.

destructive distillation of calcium acetate gives acetone right? not acetaldehyde

draculic acid69 - 31-3-2019 at 07:33

Calcium acetate intimately mixed with calcium formate apparently yeilds acetyldehyde and if the mixing is inadequate probably some acetone as well.further back in the thread someone claims to have made 200 mls of acetyldehyde by this method. Also apparently acetylene bubbled through a hgso4 solution yeilds acetyldehyde. Formates + other carboxylic acid salts yeilds the corresponding aldehyde is a well known thing.

[Edited on 31-3-2019 by draculic acid69]

VLE Data

Photonic - 10-4-2019 at 21:20

Would anyone by chance have access to vapor-liquid-equilibrium data for Acetaldehyde, Ethanol, and Water or any combination thereof?

I am looking for a boiling point chart for varying concentrations.

I do not currently have access to Dortmund data bank, and am unable to find this data on sciencedirect or similar papers.

Thanks kindly.

Corrosive Joeseph - 3-6-2019 at 09:01

Quote: Originally posted by S.C. Wack  
Page 4686 of JCS (1956) claims a 50% yield by reflux of EtOH with excess MnO2 for 20 min. No explicit experimental is given in this case. A number of aldehydes and a few ketones are prepared, but my copy (from microfilm) is of poor quality.


Barakat et al. - Oxidation of Organic Compounds by Solid Manganese Dioxide - Notes, Journal of the Chemical Society (1956) Pages 4685-4687


CJ

Attachment: Barakat et al. - Oxidation of Organic Compounds by Solid Manganese Dioxide.pdf (226kB)
This file has been downloaded 947 times


Corrosive Joeseph - 30-6-2019 at 16:07

Machine translation, with tweaks from another member

Quote:


L. Rosenthaler:

Notes on the Behavior of Monohydric Alcohols towards Ferrous Sulfate and Hydrogen Peroxide.

(Communication from the Pharmaceutical Institute of the University of Bern.)

Received on September 10, 1929.


The English chemist Fenton is known to have fundamental valuable studies on the reactions of organic substances with hydrogen peroxide in the presence of ferrous salts ausr guided. These studies also have a biochemical interest, since we know through the examinations of Warburgs, which role iron plays in the oxidation processes of the organism.
Now also monohydric alcohols oxidized in the animal organism become an indication of Fenton and Jackson [Ref.1], methyl, ethyl, propyl, isopropyl and amyl alcohol behave indifferent against Hydrogen peroxide both in the presence and in the absence of Iron and showed completely indifferent behavior, this requires further research.

The investigation was generally carried out with a fifth of mol. of Alcohol in at least 200g of water (less soluble alcohols in as much water as is required for complete solution) dissolved, after dissolution of 6 g of ferrous sulfate, 20 g of hydrogen peroxide (30%) were added.
After 24 hours, the reaction was distilled. The distillate was added to calcium carbonate and re-distilled.
With the distillate the reactions of aldehydes employed and the p-Nitrophenylhydrazone was prepared, and from the distillation residues the calcium and silver salt were produced.

The results were the following:

Methanol: Formaldehyde and formic acid were formed, as evidenced by the usual qualitative reactions.

Ethanol: Acetaldehyde and Acetic acid were detected.

p-Nitrophenylhydrazone, Fp. 128°.
0.0639 g Sbst.: 13.9 ccm N (17°, 711 mm).
Ber.: N 23.47.
Gef.: N 23.48.

Silver salts.
0.2340 g Sbst.: 0.1514 g Ag.
Ber.: Ag 64.64.
Gef.: Ag 64.14.


n-Propanol: n-Propylaldehyde and Propionic acid were detected.

p-Nitrophenylhydrazone.
0.0582 g Sbst.: 12 ccm N (20°, 716 mm).
Ber.: N 21.77.
Gef.: N 22.08.

Silver salts.
Ber.: Ag 59.63.
Gef.: Ag 60.3.

Isopropanol: Acetone (by the reactions of Legal and Deniges, the iodine ammonia reaction u. a.) and acetic acid were detected.
The latter is made of acetone, which, like was found experimentally in the oxidation with hydrogen peroxide and ferrous sulfate, except formic acid, formaldehyde (indicated by the qualitative reactions) and supplied acetic acid.
For the proof of the acetic acid the calcium salts of the Formic acid and acetic acid-containing solution (see above) with silver nitrate heated until the acid was completely decomposed to the end. The silver which crystallized from the filtrate became silver and was analyzed.

0.1940 g Sbst .: 0.1255g Ag.
Ber.: Ag 64.64.
Gef.: Ag 64.4.

It may then be considered safe, that also in the oxidation of isopropyl alcohol with hydrogen peroxide and ferrous sulphate, acetic acid is formed.


n-Butyl, iso-Butyl and iso-amyl alcohol can be oxidized by hydrogen peroxide and ferrous sulfate also to aldehydes and acids, as the reductions of them, and the preparation of p-nitrophenylhydrazones and silver salts, have confirmed.
The analysis did not gave the values normally expected.
It is undoubtedly related to this that the acidic acids present were further oxidized by hydrogen peroxide and ferrous sulfate.
In fact, we know from earlier experiments, from Dakin, that certain fatty acids are already attacked by hydrogen peroxide alone.
The addition of ferrosulphate could only increase the oxidizing strengths at most.
An experiment showed that when butyric acid was oxidised with hydrogen peroxide and ferrous sulfate, a p-Nitrophenylhydrazone compound was obtained from the distillate.

Conclusion: The monovalent alcohols of methyl to Amyl alcohol are contrary to the data of Fenton and Jackson oxidized by hydrogen peroxide and ferrous sulfate.




/CJ

Corrosive Joeseph - 30-6-2019 at 17:51

Sugimoto, H., & Sawyer, D. T. (1984).
Iron(II)-induced activation of hydrogen peroxide to ferryl ion (FeO2+) and singlet oxygen (1O2) in acetonitrile: monoxygenations, dehydrogenations, and dioxygenations of organic substrates.

Journal of the American Chemical Society, 106(15), 4283–4285.


/CJ

Attachment: Iron(II)-induced activation of hydrogen peroxide - Sugimoto & Sawyer (1984).pdf (390kB)
This file has been downloaded 762 times


Corrosive Joeseph - 2-7-2019 at 17:38

"We have oxidised a wide variety of organic substances with manganese dioxide.
Hydroxy-compounds were oxidised to carbonyl compounds, and aromatic aldehydes gave the corresponding
carboxylic acids. Polybasic hydroxy-acids (eg., tartaric) in ice-cold solution gave carbon dioxide and acetaldehyde"

Leoncini, Chemisches Zentralblatt, nb. I; (1910); p. 1655


Request.....


/CJ

Corrosive Joeseph - 5-7-2019 at 15:59

The above post is pretty redundant and it's too late to edit -

Some Ethanol to Acetaldehyde references without chromates or a hot copper tube......... The first 4 are posted above.


Barakat et al. - Oxidation of Organic Compounds by Solid Manganese Dioxide
Notes, Journal of the Chemical Society (1956) Pages 4685-4687
With MnO2, no solvent.
Polybasic hydroxy-acids (eg., tartaric) and MnO2 gave carbon dioxide and acetaldehyde.

Rosenthaler; Archiv der Pharmazie (Weinheim, Germany); (1929); p. 600
With dihydrogen peroxide, iron(II) sulfate in water.


With dihydrogen peroxide, iron(II) in acetonitrile, Yield given. Yields of byproduct given
Sugimoto, Hiroshi; Sawyer, Donald T.; Journal of the American Chemical Society; vol. 106; nb. 15; (1984); p.
4283 - 4285






Leoncini, Chemisches Zentralblatt, nb. I; (1910); p. 1655
Tartaric acid and MnO2 gave carbon dioxide and acetaldehyde


Gelissen; Hermans; Chemische Berichte; vol. 58; (1925); p. 768
With dibenzoyl peroxide


Courtot; Chemisches Zentralblatt; vol. 81; nb. I; (1910); p. 1847
With iodine


Mathieu; Chemisches Zentralblatt; vol. 76; nb. II; (1905); p. 782
With air, ethanol, for simple contact, dilute fluids; the education is promoted if the solution is oxydable
Bodies such as SO2, FeSO4, FeO, MnO, etc .; Sunlight increases the oxidation.


Spoehr; Biochemische Zeitschrift; vol. 57; (1913); p. 107
With air, Irradiation.im ultravioletten Licht


Sykora, Jan; Jakubcova, Maria; Cvengrosova, Zuzana; Collection of Czechoslovak Chemical Communications;
vol. 47; nb. 8; (1982); p. 2061 - 2068
With copper dichloride in acetonitrile, Time= 0.75h, T= 20 °C , Irradiation, other concentrations of CuCl2, Quantum
yield


Stepuro, I. I.; Ignatenko, V. A.; Oparin, D. A.; Russian Journal of Physical Chemistry; vol. 64; nb. 7; (1990); p. 951
- 956; Zhurnal Fizicheskoi Khimii; vol. 64; (1990); p. 1774 - 1782
With dihydrogen peroxide, iron(III) chloride in water, other catalysts, variation of conditions, Product distribution, Kinetics


With borax, sodium perchlorate, iodine, potassium iodide in water, Time= 1h, T= 35 °C , the effect of pH, other solvents,
other temp., neutral salts, stoicheiometry; Kinetics, Mechanism, Thermodynamic data
Sharma, Satish Kumar; Manglik, Anita; Gazzetta Chimica Italiana; vol. 112; nb. 5/6; (1982); p. 239 - 242

With zinc(II) oxide in tetrahydrofuran, toluene, UV-irradiation
Carroll, Gerard M.; Schimpf, Alina M.; Tsui, Emily Y.; Gamelin, Daniel R.; Journal of the American Chemical Society;
vol. 137; nb. 34; (2015); p. 11163 - 11169


1.1 : First, the preparation of acetaldehyde
Copper acetate solid weighed one kilogram of ethanol, fully milled 500 g (the copper acetate powder 20-40 mesh),
after the dehydrogenation reaction of acetaldehyde.
With copper acetate, Large scale
Patent; Kureha Chemicals Shanghai Co. Ltd.; Ding, Hui; (5 pag.); CN105367542; (2016); (A) Chinese


With potassium ferrate(VI), sodium hydroxide in aq. phosphate buffer, T= 25 °C , pH= 9.5, Kinetics
Xie, Jianhui; Lo, Po-Kam; Lam, Chow-Shing; Lau, Kai-Chung; Lau, Tai-Chu; Dalton Transactions; vol. 47; nb. 1;
(2018); p. 240 - 245


With sodium hypochlorite, iron(III) chloride hexahydrate in water, Time= 4h, T= 20 °C , p= 760.051Torr , UV-irradiation,
Catalytic behavior, Reagent/catalyst
Makhmutov; Russian Journal of General Chemistry; vol. 88; nb. 5; (2018); p. 892 - 897; Zh. Obshch. Khim.; vol. 88;
nb. 5; (2018); p. 747 - 753,7


With dihydrogen peroxide in aq. buffer, pH= 5, Irradiation
Wang, Chen; Shi, Yi; Dan, Yuan-Yuan; Nie, Xing-Guo; Li, Jian; Xia, Xing-Hua; Chemistry - A European Journal;
vol. 23; nb. 28; (2017); p. 6717 - 6723


With sodium hypochlorite, iron(III) chloride hexahydrate in water, T= 100 °C
Makhmutov; Russian Journal of General Chemistry; vol. 88; nb. 5; (2018); p. 892 - 897; Zh. Obshch. Khim.; vol. 88;
nb. 5; (2018); p. 747 - 753,7


With nitric acid, Time= 8h, T= 79.84 °C
Jasinska, Jadwiga; Krzyzynska, Beata; Kozlowski, Mieczyslaw; Central European Journal of Chemistry; vol. 9;
nb. 5; (2011); p. 925 - 931


With hydrogenchloride in water, Time= 12h, T= 24.84 °C , UV-irradiation, Inert atmosphere, Catalytic behavior, Reagent/
catalyst
Weng, Bo; Quan, Quan; Xu, Yi-Jun; Journal of Materials Chemistry A; vol. 4; nb. 47; (2016); p. 18366 - 18377


With nickel iron copper catalyst, T= 200 °C , Kinetics, Mechanism, Reagent/catalyst
Kumar; Miller; Mukasyan; Wolf; Applied Catalysis A: General; vol. 467; (2013); p. 593 - 603


With sodium hydroxide in water, Time= 1.5h, T= 20 °C , Irradiation, Inert atmosphere, Kinetics, Catalytic behavior,
Concentration
Markovskaya; Kozlova; Kinetics and Catalysis; vol. 59; nb. 6; (2018); p. 727 - 734; Kinet. Katal.; vol. 59; nb. 6;
(2018); p. 685 - 693,9


There's more, but that'll do for now.


/CJ

Corrosive Joeseph - 5-7-2019 at 16:36

More........ And related literature.


/CJ

Attachment: The Oxidation of Ethanol by H2O2 Part I. Catalysis by Ferric Ion.pdf (577kB)
This file has been downloaded 848 times

Attachment: Efficient solvent-free iron(III) catalyzed oxidation of alcohols by H2O2 - Martin and Garrone (2002).pdf (258kB)
This file has been downloaded 769 times

Attachment: Copper Catalysts For Alcohol Oxidation - J. Ahmad (Helsinki) (2012).pdf (1.4MB)
This file has been downloaded 1962 times

Attachment: Epoxidation of Alkenes with Bicarbonate-Activated H202.pdf (110kB)
This file has been downloaded 737 times

Attachment: The Oxidation of Cinnamaldehyde with Alkaline H2O2 to Benzaldehyde.pdf (553kB)
This file has been downloaded 697 times

Attachment: Autocatalytic oxidation of nitrobenzene using H2O2 and Fe(III) - Nichela (2008).pdf (596kB)
This file has been downloaded 749 times


Corrosive Joeseph - 9-7-2019 at 14:46


Bataineh, Hajem; Pestovsky, Oleg; Bakac, Andreja; ACS Catalysis; vol. 5; nb. 3; (2015); p. 1629 - 1637


100% yields using ethanol, oxygen, iron(III) perchlorate, ozone,
Kinetics, Reagent/catalyst, Concentration Parameters Experimental data



/CJ



Attachment: Iron(II) Catalysis in Oxidation of Hydrocarbons with Ozone in Acetonitrile.pdf (672kB)
This file has been downloaded 725 times

Corrosive Joeseph - 13-8-2019 at 10:22

Thanks to S.C. Wack for finding these.........Machine translations, with tweaks from another member.


Quote:


Leoncini, Chemisches Zentralblatt, nb. I; (1910); p. 1655


Effect of manganese peroxide in winemaking on tartaric acid.


If you treat aq. solution of tartaric acid with MnO2 in the heat, at 35 °C CO2-evolution begins. At the same time acetaldehyde forms:

C4H6O6 + MnO2 = 2CO2 + CH3COH + H2O + MnO + O.

The reaction is at approx. 80 °C complete and can be used for aldehyde synthesis. If MnO2 is in excess, all tartaric acid decomposes; if this is not the case, additionally a white, insoluble powder of manganese tartrate C2H2(OH)2(COO)2Mn is formed.
If this salt remains in the tartaric acid solution, it turns into a crystalline, reddish powder in C2H2 (OH)2(COO)2Mn + 2H2O, which loses its water at 100 °C. A decomposition of tartaric acid also takes place when no more MnO2 is present, but only the soluble manganese tartrate.
Also, MnO2 acts in the same way on soluble acidic tartrates and on acids containing the group - CH(OH), such as malic and citric acid.

Wines, whose must ( https://en.wikipedia.org/wiki/Must ) has been treated with MnO2, will contain more aldehyde compounds, except for the aldehyde that arised due to direct incorporation of MnO2 on alcohol.
Furthermore composites of ethers, acetals and volatile acids will be present and such a wine would have the characteristics of an old wine.
The disadvantage would be the reduction of tartaric acid and hence the shelf life and the content of Mn salts.
A vinegar made with MnO2 and containing much Mn salts showed a normal taste.
When using the MnO2 for winemaking a presumably harmful action of Mn should be noted.

(Stasi Sperm Agrarian, Italian, 43. 33-45 [November 1909. Pisa, Laboratory for Agricultural Chemistry, K. Univ.)




Quote:


C. Courtot - Chemisches Zentralblatt; vol. 81; nb. I; (1910); p. 1847


change in tincture of iodine.


In order to be able to follow the changes over time in the tincture of iodine, which, as it turned out, existed in the formation of HI, aldehyde and ethyl acetate.
Author prepared a solution of 67.5 g Iodine in 1000ml of 90% ethanol, a second of 67.5 g of iodine and 0.3 g of acetaldehyde in 1000ml of 90% ethanol and a third of 67.5 g of iodine and 0.3 g of acetaldehyde in 1000ml of absolute alcohol.
And in this solution at monthly intervals determined the content of free iodine, HI, aldehyde, and ethyl acetate.

This determination gave the following.
In the tincture of iodine (Lg. 1) forms HI, acetaldehyde and ethyl acetate. After the reaction, Iodine acts on the alcohol with the formation of HI and aldehyde.



C2H5OH + 2I = 2HI + CH3CHO.

The aldehyde is then oxidized to H 2 and acetic acid by the iodine and the water contained in the tincture:

H2O + 2I + CH3CHO = CH3COOH + 2HI

The acetic acid is esterified to the extent of its formation by the ethanol. In the first two months after the preparation of the tincture (Lg. 1) these reactions are very effective, but then weaken constantly and progressively, since they are affected by the hydrogenating properties of the HI.
Their quantity by the first two reaction is enlarged, paralyzed. After 7-8 months the working of this reaction is equal to zero, and the composition -
The tincture (Lsg. 1) has become a constant - 54.610 g of iodine, 12.799 g of HI, 0.195 g of aldehyde, 1.936 g of ethyl acetate.
The iodine-rich tincture of the new codex undergoes the same changes.

(Journ Pharm-et Chim. 1. [7] 297-301 .16 / 3. 354-59. 1/4.)




Quote:


L. Mathieu - Chemisches Zentralblatt; vol. 76; nb. II; (1905); p. 782


On the spontaneous oxidation of ethyl alcohol.


Author reports on a number of attempts that followed the formation of aldehyde in ethanol containing flakes. In this case, the following results were found:

1. In wines and ethanol of the same strength, aldehyde forms in simple contact of the alcohol with the air at ordinary temperature and without co-weight of porous bodies or microorganisms. -

2. This process is considerably accelerated if the solution contains oxidizable bodies such as SO2, FeSO4, FeO, MnO, etc. -

3. The sunlight increases the oxidation. -

4. Green glass vessels favor oxidation less than colorless.

The acceleration of the exothermic formation of the aldehyde by reducing agent is one of the phenomena that Berthelot (C.R. d. L'Acad. Of science 124 June) by the exothermic reaction. In the case of these oxidation processes, Bertrand (C. de l'Acadé of Science, 124 June) has put forward a very satisfactory theory.

The present observations have special significance for the legal definition of the limit numbers for aldehyde and SO2, in wines and the like. Spirits, for the analysis and the storage of alcoholic samples.
(Forts, follows.) (Bull, de l'Assoc. Of Chim. De Sucr. And Dist., 22nd, 1283-93, June, Beaune, Oenological Stat.)




Quote:


Spoehr - Biochemische Zeitschrift; vol. 57; (1913); p. 107


Ethyl alcohol is easily oxidized under the action of ultraviolet rays in the presence of atmospheric oxygen. There is plenty of carbon dioxide, also formic acid, acetic acid and traces of oxalic acid, and of course a lot of acetaldehyde.




/CJ


[Edited on 14-8-2019 by Corrosive Joeseph]

Corrosive Joeseph - 23-8-2019 at 19:31

With zinc(II) oxide in tetrahydrofuran, toluene, UV-irradiation

Redox Potentials of Colloidal n-Type ZnO Nanocrystals: Effects of Confinement, Electron Density, and Fermi-Level Pinning by Aldehyde Hydrogenation
Gerard M. CarrollAlina M. SchimpfEmily Y. TsuiDaniel R. Gamelin

J. Am. Chem. Soc. 2015, 137 34 11163-11169


/CJ

Attachment: With zinc(II) oxide in tetrahydrofuran, toluene, UV-irradiation.pdf (1.7MB)
This file has been downloaded 700 times


Corrosive Joeseph - 23-8-2019 at 23:31

^^^^^^^^^

https://www.sciencemadness.org/talk/viewthread.php?tid=15334...


/CJ

Corrosive Joeseph - 26-8-2019 at 13:57

With potassium ferrate(VI), sodium hydroxide in aq. phosphate buffer, T= 25 °C , pH= 9.5, Kinetics

Xie, J., Lo, P.-K., Lam, C.-S., Lau, K.-C., & Lau, T.-C. (2018).
A hydrogen-atom transfer mechanism in the oxidation of alcohols by [FeO4]2− in aqueous solution.
Dalton Transactions, 47(1), 240–245.


With nickel iron copper catalyst, T= 200 °C , Kinetics, Mechanism, Reagent/catalyst

Kumar, A., Miller, J. T., Mukasyan, A. S., & Wolf, E. E. (2013). In situ XAS and FTIR studies of a multi-component Ni/Fe/Cu catalyst for hydrogen production from ethanol.
Applied Catalysis A: General, 467, 593–603.


/CJ

Attachment: With potassium ferrate(VI), sodium hydroxide in aq. phosphate buffer.pdf (1.4MB)
This file has been downloaded 805 times

Attachment: With nickel iron copper catalyst.pdf (2.3MB)
This file has been downloaded 673 times

Corrosive Joeseph - 6-9-2019 at 16:07

Sykora, Jan; Jakubcova, Maria; Cvengrosova, Zuzana; Collection of Czechoslovak Chemical Communications;
vol. 47; nb. 8; (1982); p. 2061 - 2068
With copper dichloride in acetonitrile, Time= 0.75h, T= 20 °C , Irradiation, other concentrations of CuCl2, Quantum
yield


With dihydrogen peroxide, iron(III) chloride in water, other catalysts, variation of conditions, Product distribution, Kinetics
Stepuro, I. I.; Ignatenko, V. A.; Oparin, D. A.; Russian Journal of Physical Chemistry; vol. 64; nb. 7; (1990); p. 951
- 956; Zhurnal Fizicheskoi Khimii; vol. 64; (1990); p. 1774 - 1782


With sodium hypochlorite, iron(III) chloride hexahydrate in water, T= 100 °C
Makhmutov; Russian Journal of General Chemistry; vol. 88; nb. 5; (2018); p. 892 - 897; Zh. Obshch. Khim.; vol. 88;
nb. 5; (2018); p. 747 - 753,7



/CJ

Attachment: Photooxidation effect of cupric complexes on aliphatic alcohols in nonaqueous solutions.pdf (256kB)
This file has been downloaded 649 times

Attachment: RusJPhysChem1990.PDF (518kB)
This file has been downloaded 704 times

Attachment: makhmutov2018.pdf (249kB)
This file has been downloaded 668 times

[Edited on 7-9-2019 by Corrosive Joeseph]

Quieraña - 29-12-2019 at 13:59

There is a video on YouTube by the channel thoi SOI 2 he used chromium oxide cr203 the green stuff which I had once had in my possession following the YouTube channel "explosions and Fire" or was "extractions and ire" same guy anyway for making chromate and dichromate from stainless steel but chromium oxide is easy to come by and doesn't require bleach or oxidizer to make:

simply placing a cotton ball soaked in ethanol into a pile or pouring a pile of chromium oxide (I mean for you to completely cover the cotton with green and not just barely covered not like breadcrumbs but like two-to-one ratio chromium oxide to cotton ball by visual) igniting the cotton and the glow that is sustained underneath the pile of chromium oxide is made by the oxide and when the glow is done there is acetaldehyde in its place and acetic acid I don't know the percentage yet I imagine many cotton balls later you have acetaldehyde of measurable quantity.

Cou - 20-1-2020 at 15:25

couldn't you just do this with ethanol instead of 1-propanol? https://www.youtube.com/watch?v=T9ha_MS1S9o

Cou - 19-6-2020 at 01:50

and couldn't you just use PCC with ethanol?

karlos³ - 19-6-2020 at 04:53

Of course but where is PCC easier or cheaper than simple dichromate oxidation?

Cou - 19-6-2020 at 17:04

Then it seems you could just use Nile reds method for propionaldehydw, unless there is some azeotrope issue I'm missing that prevents it for acetaldehyde.

karlos³ - 19-6-2020 at 18:52

Like here: https://www.prepchem.com/synthesis-of-acetaldehyde/
Yes, I did that a few times already.

And it depends, what is your intention with it? The ethanol in the acetaldehyde isn't always a problem.
Or rather, most of the uses I can think of right now don't suffer from the ethanol impurities.

I used that ethanol contaminated acetaldehyde without an issue... I made even more ethanol into it and used that in a fermentation to react with a specific enzyme instead of the substrate I was using.
Of course a bad example as I needed it in ethanol :P

What are your plans for the propionaldehyde?

Cou - 19-6-2020 at 18:56

I like aldehydes for making an assortment of alcohols.

karlos³ - 19-6-2020 at 19:18

If you'd like to, could you explain that? What I understand is, oxidising 1-propanol to the aldehyde, then making an alcohol out of it?
Surely must have gotten that completely wrong?

Cou - 20-6-2020 at 10:34

I mean using aldehydes in grignard reactions to make alcohols.

Jenks - 15-9-2020 at 09:11

Today I was watching an excellent video on making dioxane from ethylene glycol. Copious amounts of acetaldehyde, from elimination of the ethylene glycol by sulfuric acid, was the main "unwanted" side product:

https://www.youtube.com/watch?v=9Zzrn-61XAY&t=333s

clearly_not_atara - 16-9-2020 at 06:21

In reality producing acetaldehyde isn't all that hard. What is hard is producing acetaldehyde in significant quantities and in such a way that it can be separated from the reaction mixture, condensed, and isolated.

It's difficult, for example, to condense a compound with bp 20 C when that compound is co-produced in the efflux stream with much larger quantities of water, bp 100 C, and when said gas stream emerges at nearly 200 C.

It is likewise not very easy to isolate acetaldehyde from aqueous rxn mixtures since its bisulfite adduct is not as insoluble as those of larger aldehydes, and it may polymerize under the alkaline conditions typically used for bisulfite adduct deprotection. Bisulfite adducts may also be deprotected with acid, but this produces copious SO2.

As such, the great majority of syntheses posted in this thread are not really solving the right problem. IMHO, if you want a practical synth of acetaldehyde, what you're really after is an oxidation of ethanol that produces 1,1-diethoxyethane -- acetaldehyde diethyl acetal -- in situ. This compound can easily be separated from the reaction mixture and pure acetaldehyde obtained by acidic cleavage under relatively mild conditions with few co-products. It is stable and can be stored.

To that end, I offer the direct photocatalytic oxidation of ethanol to 1,1-diethoxyethane over two catalysts: 1% Pt-doped TiO2 nanorods and Cd-Ni-Mo sulfide.

https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10...

https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10....

While the photocatalysts take a little work -- hardly impractical IMO -- they offer the possibility of one-step large-scale production of DEE qua acetaldehyde in a form that is stable and easy to isolate and store.

But be aware that while acetals such as DEE usually do not form peroxides, the risk must not be ignored.

Attachment: zhang2015.pdf (849kB)
This file has been downloaded 708 times

Attachment: chao2018.pdf (3.4MB)
This file has been downloaded 818 times


Triflic Acid - 5-11-2020 at 17:53

I see this threads been dead for a while :P, but this paper outlines a way of oxidizing alcohols using O2 over some Pd/C like catalysts. https://pubs.acs.org/doi/pdf/10.1021/cr0200116

[Edited on 6-11-2020 by Triflic Acid]

NaK - 24-11-2020 at 13:54

Quote: Originally posted by Corrosive Joeseph  
Quote: Originally posted by S.C. Wack  
Page 4686 of JCS (1956) claims a 50% yield by reflux of EtOH with excess MnO2 for 20 min. No explicit experimental is given in this case. A number of aldehydes and a few ketones are prepared, but my copy (from microfilm) is of poor quality.


Barakat et al. - Oxidation of Organic Compounds by Solid Manganese Dioxide - Notes, Journal of the Chemical Society (1956) Pages 4685-4687


CJ


Did anyone try this method yet? It seems like the most convinient method...

EverythingAl2O3 - 2-12-2020 at 12:43

It might just be easier to attempt to partially dehydrate ethylene glycol. An enol will form and tautomerize. It could be done pretty easily with say H2SO4, H3PO4 or Al2O3. Though if there if there is a reason why it wouldn't work someone let me know.

Jenks - 14-4-2021 at 10:33

Quote: Originally posted by EverythingAl2O3  
It might just be easier to attempt to partially dehydrate ethylene glycol. An enol will form and tautomerize. It could be done pretty easily with say H2SO4, H3PO4 or Al2O3. Though if there if there is a reason why it wouldn't work someone let me know.

Forgive me for not reading this thread, but what about NurdRage's YouTube videos for producing sodium? He purifies sodium by boiling it in dioxane, which he produces from ethylene glycol and sulfuric acid. And the side product in that production is the ethylene glycol acetal of acetaldehyde. He vents a ton of acetaldehyde saying to get rid of that nasty carcinogen. Opportunity abounds. I plan to use this myself as a way to produce dioxane plus the acetaldehyde I require.

draculic acid69 - 14-4-2021 at 17:41

Quote: Originally posted by Jenks  
Quote: Originally posted by EverythingAl2O3  
It might just be easier to attempt to partially dehydrate ethylene glycol. An enol will form and tautomerize. It could be done pretty easily with say H2SO4, H3PO4 or Al2O3. Though if there if there is a reason why it wouldn't work someone let me know.

Forgive me for not reading this thread, but what about NurdRage's YouTube videos for producing sodium? He purifies sodium by boiling it in dioxane, which he produces from ethylene glycol and sulfuric acid. And the side product in that production is the ethylene glycol acetal of acetaldehyde. He vents a ton of acetaldehyde saying to get rid of that nasty carcinogen. Opportunity abounds. I plan to use this myself as a way to produce dioxane plus the acetaldehyde I require.


Many ppl have done this rxn for the dioxane but no one yet has done this for the purpose of capturing and measuring the yeild of the acetaldehyde. If U do this
please report back with yeild.it would contribute to this thread greatly

EverythingAl2O3 - 28-4-2021 at 16:56

Have we also considered the Corey-Kim oxidation? N-chlorosuccinimide with a unhindered thioether and a tertiary amine/hindered amine like triacetoneamine. Yes DMS would be pretty smelly, but if one can make a long chain sulfide (Wikipedia says dodecyl methyl sulfide was used as a less noxious sulfide) it wouldn't be as much of an issue. NCS can be regenerated by reacting Succinimide with bleach. Only downside is cooling to around -40 to -25C and 10h ish reaction time. But the reagents can be regenerated with cheap chemicals.

Opylation - 5-6-2021 at 19:32

Quote: Originally posted by EverythingAl2O3  
Have we also considered the Corey-Kim oxidation? N-chlorosuccinimide with a unhindered thioether and a tertiary amine/hindered amine like triacetoneamine. Yes DMS would be pretty smelly, but if one can make a long chain sulfide (Wikipedia says dodecyl methyl sulfide was used as a less noxious sulfide) it wouldn't be as much of an issue. NCS can be regenerated by reacting Succinimide with bleach. Only downside is cooling to around -40 to -25C and 10h ish reaction time. But the reagents can be regenerated with cheap chemicals.


That seems a little much for acetaldehyde, don’t you think? If you want a cheap and easy way of getting acetaldehyde as a reagent, metaldehyde - acetaldehyde tetramer - is available in bulk from Chinese sellers. It is the active ingredient in slug killer

EDIT: it is also available in the US in slut bait, but only at 3-5% and it is not the best to work with. It can be sublimed but the slug bait, at least the kind I used, was a black goo that smelled a special kind of rank, especially when heated. Also, while sublimation is an effective way of separating the crystalline material it is a very very very VERY long and tedious process and I gave up after only a few grams (took me all day a while back)

[Edited on 6-6-2021 by Opylation]

EverythingAl2O3 - 6-6-2021 at 07:19

Yes it is a bit much for it. Though it seems far more regenerable than using Chromate oxidizers mentioned before in the thread. I think using hypochorite in glacial acetic acid might work better than anything else, but need to actually test to make sure it doesn't over oxidize.

theAngryLittleBunny - 12-9-2021 at 02:43

Did anyone think about dry distillation of a mixture of calcium acetate with a huge excess of calcium formate? It should produce a lot of formaldehyde which just escapes, and quite a bit of acetaldehyde with some acetone that can be collected. Then you just need to separate the acetone either by distilling out the acetaldehyde or adding a bit of acid to turn it into paraldehyde and distill off the acetone.

Unless someone knows that it doesn't work, I'll have to give this a try, I just need to buy some formic acid.

EDIT: Okay, I decided to finally try it instead of just theorizing, I got really good yields for a high boiling ketone that way, so this seems promising to me, I'll report back when I'm done.

[Edited on 12-9-2021 by theAngryLittleBunny]

Reagents?

tetrogen - 10-12-2021 at 10:27

I came across a few experiments I want to try and need acetaldehyde.
I drew out a few mechanisms which would bring me there, which seem a bit different from the routes used here. Perhaps its because the reagents are not so easy to get.

1. Swern oxidation of ethanol (DMP or PCC could be used, also Chromic acid via various dichromates and chromates)
2. keto-enol tautomerization of acetalyne using NaBH3, THF & H2O2, NaOH
3. Convert acetonitrile to acetaldehyde with DiBAL-H

Has anyone tried any of these methods? They are all very simple, textbook examples it seems. Are any of these reagents accessible without "borrowing" from your lab?
I'm pretty new to at-home chemistry, and the labs I've been in for university just have everything on hand. Can one just order reagents such as PCC through major suppliers like Sigma?


timescale - 10-12-2021 at 11:14

Quote: Originally posted by tetrogen  
Are any of these reagents accessible without "borrowing" from your lab?
I'm pretty new to at-home chemistry, and the labs I've been in for university just have everything on hand. Can one just order reagents such as PCC through major suppliers like Sigma?


One can usually not order reagents directly from Sigma/Alfa/etc. The exception is if you have a bona fide lab or commercial address that you can use, and it may be difficult even then.

Many reagents can be found/extracted/produced from "over the counter" materials. PCC for example is certainly accessible to the amateur.

Also, there are individuals and companies that will act as middlemen between you and these suppliers, for a fee. Some individuals advertise these services on the Reagents and Apparatus Acquisition forum. Chemsavers is good for the more exotic chemicals. DMP is available through them...

... as well as acetaldehyde itself :D But where's the fun in that?

tetrogen - 10-12-2021 at 20:22

Thanks for the info. I've been having fun with extracting reagents and elements from OTC products as opposed to just purchasing everything as-is, so I don't mind that.

I wasn't aware that PCC was one I could find in an OTC product, so I'll have to look into that more. That would probably be the simplest route if it works, too.

Triflic Acid - 10-12-2021 at 21:51

You can't get PCC OTC, but you can produce it from pottery-grade Cr2O3 and niacin, as well as a load of other reagents. Welcome to the forum.

Alkoholvergiftung - 11-12-2021 at 00:35

Why not the MnO2 , H2SO4 methode? MnO2 is easier to get the chrome compounds.
Pharmacy book says: 4 parts EtOH 80%, 6 parts MnO2 and 6 parts H2SO4 with 4 parts H2O are destilled.

tetrogen - 17-12-2021 at 13:29

Thanks. I saw the Doug's Lab video on it shortly after. If I do make it, I'll likely go that route, although he used CrO3 which is quite a bit harder to get than Cr2O3, so the latter option would be ideal.
The other method is certainly one I'll keep in mind, although the Cr methods will give me a reason to also produce pyridine, which will leave me with two useful reagents when I'm done. I will certainly post my notes if I do it.

karlos³ - 17-12-2021 at 14:34

I swear I just looked through the complete thread, I was remembering a certain method which did not include an oxidation?
Something via SN2 first from EtI and then... I don't remember?

I could swear I posted it in here?

Wanted to try this, still would, but what the hell was it even?
Do we have a second acetaldehyde thread?

If so, sorry....

Fery - 25-12-2021 at 11:40

karlos³
leading ethanol vapor over hot Cu metal?
depolymerization of metaldehyde (antislug compound)?
hydratation of acetylene over Hg2+ salt catalyst?

Parakeet - 31-1-2023 at 22:20

I recently synthesized acetaldehyde by the oxidation of ethanol using acidified potassium dichromate solution. Ethanol, potassium dichromate and sulfuric acid was mixed in a test tube and heated by a water bath. I attached a rubber tube to the test tube in order to lead and dissolve the aldehyde in few mL of chilled water.
It went pretty well. It had a characteristic smell of acetaldehyde. It also showed a positive result to the Fehling’s solution.
However, as the reaction proceeded, the solution which have dissolved the aldehyde became cloudy. Acetaldehyde should be miscible with water. I have no idea what this cloudy thing is. Does anyone have any idea?

SyntheticFunk - 1-2-2023 at 10:42

Quote: Originally posted by Parakeet  
I recently synthesized acetaldehyde by the oxidation of ethanol using acidified potassium dichromate solution. Ethanol, potassium dichromate and sulfuric acid was mixed in a test tube and heated by a water bath. I attached a rubber tube to the test tube in order to lead and dissolve the aldehyde in few mL of chilled water.
It went pretty well. It had a characteristic smell of acetaldehyde. It also showed a positive result to the Fehling’s solution.
However, as the reaction proceeded, the solution which have dissolved the aldehyde became cloudy. Acetaldehyde should be miscible with water. I have no idea what this cloudy thing is. Does anyone have any idea?



It's likely the self condensation product. Acetaldehyde has an enolizable alpha proton and is also a relatively good electrophile at the carbonyl carbon. It readily reacts with itself to for the aldol condensation product.

Alternatively acetaldehyde can trimerize through a different mechanism where the oxygens act as the nucleophile. Fortunately this trimerization is reversible in addition to being relatively stable in storage conditions.

I store my acetaldehyde as the ammonia trimer (google acetaldehyde ammonia trimer). You can get this by collecting the acetaldehyde distillate from your reaction in some organic solvent while bubbling anhydrous ammonia into it.

Parakeet - 1-2-2023 at 23:18

Thank you for the information. That explains it.

I don’t intend to use the acetaldehyde for other experiments. I just wanted to explore the science.

clearly_not_atara - 2-2-2023 at 20:15

Quote: Originally posted by clearly_not_atara  
what you're really after is an oxidation of ethanol that produces 1,1-diethoxyethane -- acetaldehyde diethyl acetal -- in situ.

Since I posted this, some authors developed a much more OTC method for the same conversion:
https://pubs.acs.org/doi/abs/10.1021/jacs.1c05976

Unfortunately, it is not available from the Kazakh communist filesharing server. But the Supporting Information shows that the electrolyte is Bu4NCl, which is a little easier to obtain than Ni-doped MoS2 or platinum.

Benignium - 3-2-2023 at 04:29

clearly_not_atara - It seems like there is another way. I went to the List of preprint repositories page on Wikipedia, tried a few of the larger multidisciplinary resources. Scienceopen produced a result for the DOI, and clicking Further versions led to U.S. Department of Energy Office of Scientific and Technical Information where the Accepted Manuscript (DOE) can be downloaded.

Thank you for the article! You do keep rolling out the hits. :)



leucine75 - 21-9-2023 at 08:33

I believe one of the major by products of producing 1,4 dioxane is acetaldehyde just use nurd rages method using anti freez and sulfuric acids yields some impure acetaldehyde on the second disatiion


Leucine75,
sorry about the Grammer




[Edited on 21-9-2023 by leucine75]

EF2000 - 20-11-2023 at 07:40

Quote: Originally posted by Benignium  
clearly_not_atara - It seems like there is another way. I went to the List of preprint repositories page on Wikipedia, tried a few of the larger multidisciplinary resources. Scienceopen produced a result for the DOI, and clicking Further versions led to U.S. Department of Energy Office of Scientific and Technical Information where the Accepted Manuscript (DOE) can be downloaded.

Thank you for the article! You do keep rolling out the hits. :)

For ones who, like me, can't open osti.gov:

Attachment: siqi-li-selective-chloride-mediated-neat-ethanol.pdf (866kB)
This file has been downloaded 217 times

BerkutSimp - 23-12-2023 at 13:42

Quote: Originally posted by plasma  
Does anybody have a synthesis for this, besides megalomanias. (I don't have sodium dichromate)


You could maybe try weakly reducing ethanoic acid?

 Pages:  1  ..  3    5