Phenylacetone (P2P) synthesis from benzaldehyde with butanone

[MadHatter]

Thank you so much for the easy and detailed synth description!
How about the hydrogen peroxide, could that be substituted? It's a really controlled chemical nowadays, and a bitch to synthesize yourself. Its mainly there as a catalyst in the reaction between the glacial acetic acid and the 3-methyl-4-phenyl-3-buten-2-one, right? What could be a good substitute?

 

[TheNut22]

It's worth looking in different online stores or normal street stores that sell H2O2 for growing plants.

 

[lalalander]

Everyone says this method has flaws. Has anyone ever really gotten significant yields with this method?

 

[Ortist]

You can also distill P2P with water, but it is very slow. However you MUST distill methyl-phenyl-nutenone under vacuum because there is significant amount of crap and MPB will not distill with water

 

[TheNut22]

This was just my polymerized P2P bullshit! And I could not distill my P2P. That's why my Leuckart didn't work any of those times I tried, and oh boy I tried..

 

[TheNut22]

When I extracted my P2P with ethyl acetate, I put little bit of drying agent in, and put it in my fridge.
I looked the liquid, and when it was about 3 hours i the fridge, the bottom layer was full of clear oil.
Is that my P2P? Can I really extract with this way?!

 

[TheNut22]

I was just water in the bottom. But my P2P was in the ethyl acetate.

 

[TheNut22]

BUT, it all went down the toilet, because it was NOT P2P. P2P is not soluble in ethyl acetate. I think it was some other product, because I did the hydrogenation of acetoxy, wrong way. Acetoxyphenylpropene I think is soluble in ethyl acetate. Correct me if I'm wrong. I dissolvne all in xylene now, 'cause they are both soluble in xylene, so I also save money.

 

[OrgUnikum]

P2P is very well soluble in EtOAc - Ethyl Acetate. It is also soluble in Benzene, Toluene, Xylene, Ether, DCM but it is only sparingly soluble in Naphta aka Shellsol aka Wundbenzin/Reinigungsbenzin. A mixture of Ethyl Acetate and Naphta 50/50 works great.

 

[TheNut22]

I read some "data" some time ago that it is just sparingly soluble in ethyl acetate. OK. Thanks.
But now I'm good. Thank you OrgUnikum for your reply also for my P2P hydrogenation. Now it went very well, with putting more solution to the base, in acetoxyphenylpropene hydrogenation. I got yellow, very "honey-like" smelling solution in xylene. This is the first time the solution is not red, because I followed your instructions to put more solution. Thanks!

 

[Ketaholiker]

Hello ,

can i go from 3-Methyl-4-phenyl-3-buten-2-one and do a electro oxidation.
Possible?

EP0247526: Electrolytic 3,4-Dimethoxyphenylacetone Preparation - [www.rhodium.ws]

Electrochemical process for converting olefins to ketones

This maybee helps also

Electrochemical Reduction of Nitroalkenes to Oximes and Amines - [www.rhodium.ws]

OTC would be super hope you guys can help electro reduction/oxidation its really cool and unsupect xD

Have a nice day

 

[TheNut22]

All those reagents to make 3-Methyl-4-phenyl-3-buten-2-one are OTC.
I'm not going to name any brand for to obtain that benzaldehyde, because "they" will take them out of those shelves, immediately. Or, even if i'm wrong about that, it's better to be little cautious about those precious reagets.

 

[TheNut22]

BUT, look the benz-hyde from artificial flavouring shelves in stores.

 

[handle]

Great let's try this one.
Step 1, underway.
45g Benzaldehyde + 200ml M.E.K bubble the HCL gas from 25ml H2SO4 over 25ml Hydrochloric acid. Turned bright red in about 30mins, now stirring.

 

[TheNut22]

Now that I have over 100 grams of water and acid/base -purified, but wet MPB (collected from few reactions),
I'm going to dry the crystal solution into crystals, that don't melt in room temperature. I can post a picture of that, and I can post a picture of the acetoxyphenylpropene as well, with the yields.

 

[TheNut22]

This is that oil (100 grams) with my peracetic acid at 21:th hour. Bubbling in room temperature.

 

[TheNut22]

I don't know why this picture went sideways, but you can see those bubbles in there, and
the cool colour what I get always in the peracetic oxidation process. The oxidation time was 24,5 hours.

 

[TheNut22]

I got 100 grams of acetoxy phenylpropene from that 100 grams of MPB. Now I'm happy!

 

[TheNut22]

When I put the P2P solution in xylene in the fridge, some particles come out. Do those particles belong to P2P, or can I filter them out? Last time I filtered them out. Was it a mistake, or is it wise to filter them out again? The solution is still raw, and not purified.

 

[TheNut22]

I have to make clear that those are not like little particles (my rusty english), but like a mass that will fall to the bottom of my beaker in the fridge. In room temp, those pieces no longer dissolve at room temperature. Can someone explain, and give guidance to me, please? I would be very happy, because I do not want to make any mistakes, 'cause I have so much P2P in the solution right now.

 

[TheNut22]

I washed the solution with ~ 12% HCL-solution x 4. and got almost clear solution. Washed many times with water also. Dried with MgSO4.

 

[OrgUnikum]

The product of the BV oxidation, the vinyl-acetate is miscible with Xylene, the P2P formed by hydrolysis is also miscible with Xylene, so anything what drops out is just crap. Filtration is a must if any of your intermediates or the final product in solvent is not clear but cloudy or turbid.