Sciencemadness Discussion Board

toluene --> benzaldehyde

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TheVoid - 6-6-2018 at 18:33

If your concern is the product not the science the easiest way to benzaldehyde beside buying it directly is reacting benzyl alcohol with bleach and Hcl acid as seen on youtube, the yields are remarkable if u can make a judgment call on the completion of the reaction. i made an amount of various aldehydes this way.

Sherlock Holmium - 19-6-2018 at 05:29

I suggest making benzyl chloride via radical chlorination and a subsequent sommelet reaction to form the benzaldehyde, I imagine this procedure would give far superior yields, although working with benzyl chloride is not the nicest thing in the world.

draculic acid69 - 14-8-2018 at 19:58

Has anyone actually tried the destructive distillation of calcium benzoate and calcium formate under vacuum or inert atmosphere (or it oxidized back to benzoic acid ).
Would definitely be worth trying.

sykronizer - 20-11-2018 at 22:24

If you consult more lit on that reaction, you will find that it only works for aliphatic and low molecular weight aldehydes....in any case it is stated outright that this is not a preparation method.

Refinery - 8-5-2020 at 09:27

Could sodium persulfate be substituted with sodium percarbonate in similar context?

TriiodideFrog - 2-10-2020 at 01:51

You can just purchase some bitter almond oil. It is almost pure benzaldehyde.

Fyndium - 13-10-2020 at 07:15

Quote: Originally posted by draculic acid69  
Has anyone actually tried the destructive distillation of calcium benzoate and calcium formate under vacuum or inert atmosphere (or it oxidized back to benzoic acid ).
Would definitely be worth trying.


Should definitely give a try.

I could make calcium formate instantly at hand stuff.

Calcium benzoate then.. It's not available, but sodium benzoate is.

Sodium Benzoate has solubility of 62-71g/100mL (0-100C).
Calcium Chloride has high solubility.
Calcium Benzoate has solubility of 2-9g/100mL (0-100C).

Na Benzoate + Ca Chloride = Ca Benzoate (s) + NaCl.

So the dry distillation should be performed under vacuum? Does this effect the decomp temp or is it just to protect the expected aldehyde from oxidizing?

I will put this to my to-do list. When I get time, I'll test it out, unless someone reports here that it's already been debunked.

Fyndium - 16-10-2020 at 15:13

Persulfate is used in many oxidations for BzH. What is the mechanism in this reaction and could it be substituted with, for example percarbonate or perborate instead?

Cou - 17-11-2020 at 19:40

Bromobenzene and DMF are not watched chemicals, and can be used to make benzaldehyde by the Bouveault aldehyde synthesis.
there's a limit on how far back the DEA can go in limited precursors. At a certain point it's no longer profitable.

Gualterio_Malatesta - 15-12-2020 at 07:50

Hey, guys!

There's this paper where they oxidize toluene to BA electrolytically in the presence of NaNO3 and catalytic amounts of H2SO4.

Toluene (1ml) is mixed with DCM (25ml) then water and sulfuric acid is added (5.4 ml of 37% sulfuric acid diluted with 44.6 ml of distilled water to obtain 50 ml of 0.46 M solution of sulfuric acid) and 1.18 gm of KNO3. Subsequent stirring of this solution creates an emulsion and current is applied.

Since I didn't have DCM I used isopropyl alcohol (they also tried MeOH in the paper, so I thought IPA would be ok in this reaction).

The anode (+) was carbon and cathode (-) was stainless steel.

When current (12V, 2.2A) was applied to the reaction mixture (toluene, IPA, KNO3,H2SO4 ) both anode and cathode produced a lot of gas bubbles (colorless and odorless). The temperature was kept between 30 — 40oC

The smell of toluene completely disappeared after approx 1 hour.
Reaction mixture was filtered from carbon residue to obtain homogenous dark yellow liquid with the smell of IPA and something weird (not BA).

What do you think was the gas from the electrodes and what could have this reaction yielded in the end?

[Edited on 15-12-2020 by Gualterio_Malatesta]

Sedit - 9-1-2021 at 21:19

Quote: Originally posted by Gualterio_Malatesta  
Hey, guys!

There's this paper where they oxidize toluene to BA electrolytically in the presence of NaNO3 and catalytic amounts of H2SO4.

Toluene (1ml) is mixed with DCM (25ml) then water and sulfuric acid is added (5.4 ml of 37% sulfuric acid diluted with 44.6 ml of distilled water to obtain 50 ml of 0.46 M solution of sulfuric acid) and 1.18 gm of KNO3. Subsequent stirring of this solution creates an emulsion and current is applied.

Since I didn't have DCM I used isopropyl alcohol (they also tried MeOH in the paper, so I thought IPA would be ok in this reaction).

The anode (+) was carbon and cathode (-) was stainless steel.

When current (12V, 2.2A) was applied to the reaction mixture (toluene, IPA, KNO3,H2SO4 ) both anode and cathode produced a lot of gas bubbles (colorless and odorless). The temperature was kept between 30 — 40oC

The smell of toluene completely disappeared after approx 1 hour.
Reaction mixture was filtered from carbon residue to obtain homogenous dark yellow liquid with the smell of IPA and something weird (not BA).

What do you think was the gas from the electrodes and what could have this reaction yielded in the end?

[Edited on 15-12-2020 by Gualterio_Malatesta]


If you are making Nitric acid buffered in situ which is part of what I believe this reaction is doing last thing you want is to use an Alcohol. IPA might be a bit more stable than some alcohols but no way would I put faith in it.

Maybe... idk, doubtful as well but Ethylacetate? Idk, probably not.
DCM is so easy to get almost everywhere I know of why not just use that? I'm considering this. Don't have any Nitrate though. Have Ammonia Nitrate so suppose I could just make some. Needed that for Ammonia Generation, if I get around to it I will just save the waste and see about doing this reaction.

Gualterio_Malatesta - 9-2-2021 at 01:08

Quote: Originally posted by Sedit  



DCM is so easy to get almost everywhere I know of why not just use that?


I tried DCM (and the authors mention it too and with good yields), but the reaction temp is 30-40 deg, so DCM basically boils away.

Triflic Acid - 31-3-2021 at 11:17

Has anyone thought of the messy one step version where you just dichlorinate toluene to benzal chloride. I guess if you were strategic about it, you could turn the toluene into benzal chloride by putting the temperature at the boiling point of benzyl chloride. Then, first the toluene goes into the vapor phase and forms benzyl chloride under UV which promptly condenses. After most of the toluene is gone, the temperature is ramped up with a sand bath to the boiling point of benzyl chloride, and this undergoes a second chlorination to give benzal chloride. Just add water to get benzaldehyde.

Opylation - 4-6-2021 at 10:15

This isn’t toluene, but phenol (made easily from salicylic acid) can be reacted with chloroform and sodium hydroxide in the Reimer-Tiemann reaction to form salicylaldehyde. This can be reacted with zinc powder to form benzaldehyde :)

SuperOxide - 4-6-2021 at 13:32

Quote: Originally posted by Opylation  
This isn’t toluene, but phenol (made easily from salicylic acid) can be reacted with chloroform and sodium hydroxide in the Reimer-Tiemann reaction to form salicylaldehyde. This can be reacted with zinc powder to form benzaldehyde :)


Hmm, I'm right in the middle of making some phenol to mess around with. I have all of those chemicals, I may give this a shot (after I do some research, of course).
I'll research it myself before I decide if I'll give it a go, but if you have any specific resources/links that you suggest, do share.

Have you tried that synthesis route before?

Opylation - 4-6-2021 at 14:55

I don't have any experience going through the procedure, but the salicylaldehyde synthesis via phenol and chloroform is a standard method. So is the dehydroxylation of benzene with Zn powder.


Industrial scale in mind...

flatstik - 26-11-2022 at 12:17

Quote:

The selective liquid-phase oxidation of 3,4,5-trimethoxytoluene to 3,4,5-trimethoxybenzaldehyde, an important chemical intermediate for medicine production, was developed; when 2.0 mmol of the reactant was heated at 110°C for 2 h in an autoclave under 3 atm O2 with 10 ml of acetic acid in the presence of 0.75 mmol of Co(OAc)2-Mn(OAc)2 (3:1 mole ratio), a 92% yield of the aldehyde was obtained.

https://sci-hub.se/10.1246/bcsj.61.1035


1. Do the metal acetates dissolve in GAA or not?

2. Any idea how the TMBA is extracted from the post rxn mixture? Benzaldehydes generally are soluble in GAA, so extraction with toluene would be the best option? Also, I'm not particularly interested of solid benzaldehydes, but liquid ones with electron withdrawing groups.

Is the only way to extract with some nonpolar?

It seems (https://www.journal.csj.jp/doi/pdf/10.1246/bcsj.61.967) that they use water to extract the metal acetates -- from the aldehyde is suppose? Do they then just reuse the GAA-metal salt mixture for next batch?

If this is not the case, recovering the acetic acid is a question mark as well. For example, 13.14mol rxn (2kg of the subst. toluene), 40 liters of pure acetic acid should be used. Could this be recovered somehow?

The same author has published another method for hydroxybenzaldehydes (https://sci-hub.se/10.1016/0304-5102(92)80027-E). Here no acetic acid is used, but I reckon oxygenating MeOH will yield formic acid in situ?


Quote:

Conditions: substrate, 3,5-dimethoxycresol 0.336 g (2 mmol); Ce(AcO)3 0.1 mmol; MeOH 2mL; temp. 110'C; 3 atm O2 in 50 ml autoclave; time, 5 h -- yield 95%



The extraction protocol:
Quote:

Oxygen oxidation was carried out in a 50 ml autoclave equipped with a magnetic stirrer at the desired pressure under constant temperature, using a methanol solution of the starting materials and catalysts. After a fixed time, the mixture was evaporated to remove the solvents, and the residue was extracted with EtOAc/HCl in acidic solution (HCl) to remove the catalyst. The EtOAc layer was dried over anhydrous MgSO4 and concentrated by evaporation



So, how about this: 1 mol of (un)substituted toluene is heated at 110°C for 2-5 h in an autoclave under 3 atm O2 with 1 L of MeOH per 1 mol of the substrate) in the presence of Co(OAc)2.4H2O (0.095 times the moles of substrate) of Mn(OAc)2.4H2O (0.28 times the moles of substrate)?

Still, the workup is a question. I'm quite industrial minded and steam distillation is a bitch with volumes I want to work with. I also wonder could this work with skatole (3-methylindole).

[Edited on 26-11-2022 by flatstik]

Pumukli - 26-11-2022 at 13:12

I heard that pure O2 is not really a forgiving substance when mixed with flammables.

Your suggestion of 110 C, 3 atm O2 and toluene/methanol in a vessel laced with some transition-metal ions (which are generally known as catalysts of various oxidative degradations of a wide range of compounds) sounds a bit frightening for me. Maybe I'm just a chicken though. :D

Honestly, I doubt that you can find anyone on this forum who can answer your questions with certainty. Why not ask the author(s) of the cited publication?

Waffles SS - 28-11-2022 at 22:45

Catalytic Oxidation of Toluene into Benzaldehyde and Benzyl Alcohol Using Molybdenum-Incorporated Manganese Oxide Nanomaterials

Hamza Shoukat, Ataf Ali Altaf*, Muhammad Hamayun, Shaheed Ullah, Samia Kausar, Muhammad Hamza, Shabbir Muhammad, Amin Badshah, Nasir Rasool, and Muhammad Imran
Cite this: ACS Omega 2021, 6, 30, 19606–19615
Publication Date:July 20, 2021
https://doi.org/10.1021/acsomega.1c02163




Attachment: acsomega.1c02163.pdf (4.1MB)
This file has been downloaded 338 times


[Edited on 29-11-2022 by Waffles SS]

[Edited on 29-11-2022 by Waffles SS]

Aqua-regia - 29-11-2022 at 12:30

The zinc powder is not selective. The reduction of salicylaldehyde running even to benzylalcohol and toluene.

j_sum1 - 29-11-2022 at 20:41

Quote: Originally posted by Waffles SS  
Catalytic Oxidation of Toluene into Benzaldehyde and Benzyl Alcohol Using Molybdenum-Incorporated Manganese Oxide Nanomaterials

Hamza Shoukat, Ataf Ali Altaf*, Muhammad Hamayun, Shaheed Ullah, Samia Kausar, Muhammad Hamza, Shabbir Muhammad, Amin Badshah, Nasir Rasool, and Muhammad Imran
Cite this: ACS Omega 2021, 6, 30, 19606–19615
Publication Date:July 20, 2021
https://doi.org/10.1021/acsomega.1c02163

This is a good read.
Making the catalyst looks like a good project -- remarkably accessible. (I need to check if I have manganese acetate or whether I will need to make some.)
And the synthesis of benzaldehyde looks reasonable as well. Not great yield at sub-40% and a reaction time of 18h, but pretty straightforward.

This would be worth attempting. Thanks for this, Waffles SS

Johnny Windchimes - 8-1-2023 at 14:29

Quote: Originally posted by j_sum1  
Quote: Originally posted by Waffles SS  
Catalytic Oxidation of Toluene into Benzaldehyde and Benzyl Alcohol Using Molybdenum-Incorporated Manganese Oxide Nanomaterials

Hamza Shoukat, Ataf Ali Altaf*, Muhammad Hamayun, Shaheed Ullah, Samia Kausar, Muhammad Hamza, Shabbir Muhammad, Amin Badshah, Nasir Rasool, and Muhammad Imran
Cite this: ACS Omega 2021, 6, 30, 19606–19615
Publication Date:July 20, 2021
https://doi.org/10.1021/acsomega.1c02163

This is a good read.
Making the catalyst looks like a good project -- remarkably accessible. (I need to check if I have manganese acetate or whether I will need to make some.)
And the synthesis of benzaldehyde looks reasonable as well. Not great yield at sub-40% and a reaction time of 18h, but pretty straightforward.

This would be worth attempting. Thanks for this, Waffles SS



Here ya go, for ease of reference:



Attachment: shoukat2021 - Copy.pdf (4.1MB)
This file has been downloaded 409 times

Raid - 31-5-2023 at 10:59

has anyone covered the oxidation of toluene with chromyl chloride?

(Etard Reaction)

[Edited on 31-5-2023 by Raid]

Keras - 31-5-2023 at 11:45

Quote: Originally posted by Raid  
has anyone covered the oxidation of toluene with chromyl chloride?

(Etard Reaction)

[Edited on 31-5-2023 by Raid]


I planned to do that but the idea was superseded by a much less dangerous reaction involving oxidation with cobalt chloride as a catalyser. In my case, though, I start from cresol, not toluene, and that makes a big difference.

arkoma - 31-5-2023 at 21:10

Quote: Originally posted by Raid  
has anyone covered the oxidation of toluene with chromyl chloride?

(Etard Reaction)

[Edited on 31-5-2023 by Raid]


One page back......
Quote: Originally posted by KiWiki  
Did someone try one of the Drake and Perkin methods:

1. Electrolytic oxidation of toluene, ortho-, meta-, para- xylene in acid solution is a very easy way to prepare the corresponding benzaldehyde. However, in alkaline solution toluene and meta-xylene will oxidize to carbon dioxide and water.
Source: Trans. Faraday soc., 1905, 1, 31, 251

2. Oxidation with chromyl chloride (see preparation in attachment) to the corresponding benzaldehyde. *
Source: Herbert Drake Law, Frederick Mollwo Perkin, "Oxidation of Hydrocarbons of the benzene series" , J. Chem. Soc. 91, 258, (1907)

*the modern alternative for chromyl chloride might be PCC in Silica gel for this method. I don't have access to these full articles... :(
Are there already experimental results that cover these two interestring methods?



EDIT: (by Antrax):
Perform the electrochemical oxidation with 200 to 300 mL acetone to dissolve toluene or xylene. The addition of sodium bisulfite prevents further oxidation of benzaldehyde. Use 5% to 10% 200 mL H2SO4.
70 A/h /50 g toluene or xyl. Yields are not great as sulphate ions stick to the anode and the fact that benzyl alcohol is formed.

Yields are not higher then 20%, I don't report exact experimental yields and sometimes I even don't give these yields for academic research.

[Edited on 2-1-2018 by KiWiki]


Quote: Originally posted by sykronizer  
The Toluene of commerce here in NZ and Oz is contaminated with some sulfur compounds, a sulfuric acid wash gives a dark red layer, so what ever method of oxidation we may try, I strongly suggest a clean up of the Toluene first.
After a few failures I am going to have another go at the Etard reaction, using methylene chloride as the solvent, although it's low boiling point is not ideal. It is reasonably convenient because the chromyl chloride can be prepared without having to resort to using a retort, for distilling it off. A word of caution though, do not take short cuts with solvent amounts, ie; make certain you are using at least a 25 percent dilution of the chromyl chloride to solvent, ditto for the Toluene as well, and constant stirring and cooling. My initial run was a disaster, I was too reckless, and added the chromyl far too quickly, which resulted in a sudden rise in temperature, that combined with my low boiling point solvent resulted in a stirred suspension of the adduct going from liquid to solid in about 1 to 2 seconds immediately followed by a mild explosion that covered about 4 square meters of green lumpy crap , I was uninjured thanks to my safety glasses.

Raid - 1-6-2023 at 05:07

thanks arkoma :)

arkoma - 1-6-2023 at 15:13

https://www.youtube.com/watch?v=NIVkBs7oWDI

NileRed just posted this today.

The Etard.

paulll - 1-6-2023 at 23:05

Quote: Originally posted by arkoma  
https://www.youtube.com/watch?v=NIVkBs7oWDI

NileRed just posted this today.

The Etard.

I got a bit excited when I saw, "paint thinner to cherry soda;" A new nilered about something that's actually useful. Realised right before he said it that of *COURSE* he would be busting out his Chromyl Chloride and this wasn't exactly going to be super-practical. Interesting stuff, though.



Raid - 13-6-2023 at 10:38

I wonder if I should try what NileRed is doing, I have all the reagents and I seems easy.

Edit: I'm also kinda low on ideas for stuff to do, If anyone has any ideas it would be greatly appreciated.

[Edited on 13-6-2023 by Raid]

Herr Haber - 13-6-2023 at 11:06

Quote: Originally posted by Raid  
I wonder if I should try what NileRed is doing


You can probably skip the "drink my own pee" step :)
That being said, I liked the last video a lot. It felt more like his older content: less drama /acting, more chemistry.

foxofax474 - 15-6-2023 at 22:29

Quote: Originally posted by Raid  
I wonder if I should try what NileRed is doing, I have all the reagents and I seems easy.


Instead of doing etard for benzaldehyde, maybe do the Sommelet reaction lol since it’s much cleaner and uses less carcinogens :P
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