Synthesis of 2,5-dimethoxybenzaldehyde from anise oil (small scale)

[MadHatter]

That
That's a great tip! Dimethyl sulphate is also very very nasty and not really something I'd like to whip up in my home lab. Oxalate is much preferred. Doug made some in his lab, see youtube link.
But how's the stochiometry? How much is needed to replace the sulphate?

 

[summer_child]

Sciencemadness Discussion Board - Solventless methylation with dimethyloxalate - Powered by XMB 1.9.11

I was thinking it could also be possible to start from phenol, formylate using Reimer-Tiemann and then use the Elbs persulfate oxidation to get 2,5 dihydroxybenzaldehyde , and finally methylate with DMO to the dimethoxybenzaldehyde. No need for anise oil and dichromates .
Not sure what order would give the greater yield formylation then oxidation or the other way around. But starting from phenol all the way to 2C-B i would expect something like 2.5% yield.

 

[MadHatter]

Well, the issue is OTC, as always. Anethole is really OTC, achievable in good concentrations from online sources or available through relatively simple extraction methods from anise. I used a soxhlet with good results.
Dichromate is not really OTC though, but neither is phenol. You CAN however come across potassium dichromate from pyrotechnic supply stores. It's used in several star compositions. But if oxidation is the goal, could it be replaced with KMnO4?

 

[summer_child]

Phenol can be easily made from salicylic acid.

 

[MadHatter]

Yes, but it requires relatively high temperatures and is yet another synthesis that needs to be done. Also, you need the salicylic acid. And yes, you can extract that from pain medication or skin products, but there's another thing you need to do ...

 

[summer_child]

I have some salicylic acid on hand. I might give it a try , really curious what the yield of the dimethoxybenzaldehyde would be.

 

[MadHatter]

Really exciting! I'd LOVE to see a write-up on that! I have some phenol lying around (in need of purification though, too bad it's a smelly process ...) so if you're successful I might just try too.

BTW, do you think the dichromate can be replaced with permanganate as an oxidising agent?

 

[summer_child]

https://www.researchgate.net/publication/331953336_TLC_and_GC-MS_Analyses_of_Essential_Oil_Isolated_from_Macedonian_Foeniculi_fructus

Seem so , but it required some quaternary ammonium salt. Not sure if it's crucial to the reaction.

 

[ASheSChem]

i have found this on ebay, this is the same anisaldehyde (in this synthesis)?

Anisaldehyde
4-Anisaldehyde
99% food grade
Synonym: p-Anisaldehyde, 4-Methoxybenzaldehyde, p-Methoxybenzaldehyde, Aubépine
CAS Number 123-11-5
EC Number 204-602-6
MDL number MFCD00003385

 

[MadHatter]

That would be it. Link? Shipping from?

 

[ASheSChem]

100 g anisaldéhyde 99 % FG | eBay

Find many great new & used options and get the best deals for 100 g anisaldéhyde 99 % FG at the best online prices at eBay! Free shipping for many products!

www.befr.ebay.be

 

[HIGGS BOSSON]

Different benzaldehydes
Anisaldehyde - 4-Methoxybenzaldehyde. From it, you can obtain 4-methoxy-amphetamine (PMA)
For 2c-b, DOB, N-bomes you need 2,5-dimethoxybenzaldehyde

 

[ASheSChem]

thanks

 

[summer_child]

Yes it is

 

[MadHatter]

Yes, but to produce 2,5-dmbenzaldehyde through the reaction you posted this could be the starting material, no?

 

[ASheSChem]

think the expert have reason

 

[MadHatter]

Hey man, this ships from Ukraine. You sure you'll get it with the current situation?

 

[summer_child]

It is the same precursor that is made by the first reaction.

 

[MadHatter]

Actually, I have bought reagents from this seller. Very trustworthy. But that was before the war. I actually want to buy Phtalic Anhydride from him, which is very reasonably prized and a good precursor to anthranilic acid. But I've been reluctant to, since well, you know what. So if you buy, please report back! I'd love to hear if the package comes through.

 

[ASheSChem]

this ? https://www.befr.ebay.be/itm/184667...f1I1vBmUd8cUqBE9RnYLPZNk4uq3|tkp:BFBMnoS5uKNg

if yes... a lot of step are skip ^^