Phenylacetone (P2P) synthesis from benzaldehyde with butanone

[Fenster]

Aldol Condensation.

The directions for this are in Organic Reactions



This write up seems to be more inline with what I am seeing. Has anyone actually tried to extract with solvent from the organic layer. Using chloroform won't work, as it's miscible with the organic layer. Unless I'm missing something the write up needs to be tested and modified.

Anyone tried this synth before.

 

[TheNut22]

OK. Just heat the benz-hyde and MEK with hydrochloric acid about 3-5 hours. Temp: 90-110 C.
Just thank me.

 

[TheNut22]

I got the melting point of MPB wrong, it is: 37-38°C

 

[TheNut22]

10 g benzaldehyde + 24 g MEK + 28 g hydroc.acid (~20%) = 28 g of crystals, dried in pyrex dish = 13 g of crystals.
Just keep it simple. When you are done heating, extract the brown organic layer. Wash with 40 ml of water. Extract again. Put 20 ml:s of 10% KOH-solution in. Get rid of the water. Check pH. If too acidic, or too basic, put it to 7. Get rid of the water again. Put it in freezer, because you can then, when frozen, pour the oily shit away, and get almost white crystals. Put the crystals in pyrex dish, or something and dryi it. It can liquify, but no problem. Just heat, freeze, heat, freeze, you dry those crystals, but they cannot be crispy dry. Don't know why. Maybe they are just like that.

 

[handle]

When you say, Extract.. what does that mean exactly?

 

[TheNut22]

Well, a good question. Because I like to clear that means SEPARATE the organic layer.
No solvents.. Thanks!

 

[TheNut22]

But there is one odd thing. When I don't measure pH-level at all, and just put those white crystals in my measuring flask in freezer, I get double amount of pure white crystals. Today, I made almost same amount of reagents, and same way, BUT I titrated the pH-level to 7, I got just half of the crystals. I think there is something to this. Now in the evening I just put those lame 20 ml:s of crystals in freezer, and they are orange! half of it looks like might get just oil, but I just checked there is some kind of reaction between the orange solution and upper layer white crystals that have appeared in about 10 minutes. I have come to conclusion that when you do the aldol with acid and you get basic crystals and don't titrate the pH-level at all, you get double or triple amount of Methylphenylbutenone, and when it is overnight in freezer, you dump the oil in the upper layer, and thats it. So, from now on, I don't recommend the pH-level titration.

P.S I'm sorry, I made some Methcathinone today and I'm so tired, so I'm sorry for the unclear text.
Going to sleep now.

 

[TheNut22]

Now, when I have researched this aldol, I take back my words. This is important: Do not dump the oil, because the product is in the dark oil. Just keep the dark oil, when washing it 2-3 times with water. Then make 2,5% KOH-solution. Stirr it well, and the crystals will precipitate. Check the pH, and most of the time it is over 12. Drop some hydrochloric acid in, to make pH: 7. Almost always when the pH is seven, water layer forms in the bottom. If it doesnt, put little bit water, mix, and put it in the freezer for couple of hours. When it's frozen, I take it to room temperature, and when it's in room temp, I put the erlenmeyer to my stove, and heated softly, temp off from stove. Leave it for awhile, and wait until the water layer in the bottom of the flask is fully separated (it rises little bit) so I can get ALL of the water away with pipette. When this was done, I put it in freezer, took it out, and weighed it. Also it is good to dry those crystals with stove and larger cooking glass flask (what it is called..?). Just make plenty of those crystals, put it all in this wide glass thing (i'm tired), put little bit of alcohol on top and heat it gently. It will liquify. Just continue heating. When you want to, put it in freezer. Continue this thing couple of times, when the crystals don't melt in room temperature anymore. Done! I must sleep. tell me if I wrote something stupid, and you don't get it, you know... ---> zzZZzz

 

[TheNut22]

Last time it went like this: 52.77 g of MPB ---> 37.28 g of acetoxyphenylpropene ---> 13 g of P2P.

 

[TheNut22]

My opinion to your last comment is, I think that the authorities just want to people to get caught, doing something like this and get longer sentences (manufacturing, possess to sell etc.). If they REALLY wanted to stop people to make drugs, there would be NONE drug manufacturing videos on the popular YouTube. None. If they are sensoring through YouTube even something like just one wrong word, and the video goes down, and the video maker gets some warnings, or the video maker continues to mention accidentally ONE WRONG WORD, you are out! Then there are many, even very old synthesis videos about drug and precursor syntheses, why the videos are still there, if just one word can do that.

Strange world we live in. And I think it's just a slave to the system / punishing game. I can be wrong, and maybe little dark here, but I wont go to deeper reasons now and here. Peace to all !

 

[TheNut22]

Lalalander: Benzaldehyde is the cheapest reagent by far in this projekt, because you need just 60 mls to make ~ 55 grams of water purified beige coloured crystals, that have this strong, but very pleasant smell.
And 60 mls of benzaldehyde (~ 95%) costs 6 euros.

 

[handle]

Opposite where I am, Butanone is cheap $8 Gallon, Benzaldehyde is expensive.

 

[TheNut22]

Hey. Just think about laws in my area. Shops cannot sell butanone in just plain liquid can anymore.
They can sell it in spray cans. Well, aammm.. This is also weird. NaOH is in precursor list, but you can buy KOH-pellets even from food stores. I am starting to think, what the hell are those "law regulators" smoking? Whatever it is, it must be good.

 

[handle]

Imagine a Chemical party where everyone here bring a chemical to the party n see what we get

 

[situ1988]

Can any chef give a tutorial on how to make a 100g yield?

 

[TheNut22]

Just put more reagents in the flask. Simple.

 

[Grubby]

Ya!ψ(｀∇´)ψThe RM after the reaction of benzaldehyde + MEK + HCI turns black and challenges the distillation of 3-Methyl-4-phenyl-3-buten-2-one with a boiling point of 269! This is the first time I bought a -60kpa vacuum pump for vacuum decompression and successfully obtained the golden yellow liquid 3-Methyl-4-phenyl-3-buten-2-one! But the machine seems to be overheated. Now I can only pause the distillation... Do you want the remaining rm to be completely distilled, right? I don’t want to distill out impurities with higher boiling points and ruin my hard work⋯

 

[handle]

Can you show us your vacuum pump? you know what I mean.

 

[TheNut22]

Wow! If that is the benzyldienemethylethylketone (different name to MPB), that looks very pure!
And yes, the reaction contitions will make black organic phase, when the reaction is made right.
It also looks like benzaldehyde, with same colour (boiling point: 178,1°C), and I have the info, that the product, MPB, is yellow, when it's made to oil, but I want to believe that this is the right product, and I don't want to be an asshole. Can it be distilled without a vacuum? Because now I have so much raw and not dry MPB (over 100 grams) and if it can be distilled with simple distillation, I want to make this kind of pure oil with it! Wow! Good work my friend.

 

[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.

 

[handle]

Forgot a couple of steps probably will have to redo once I get a good vacuum pump, and some sodium hypochlorite for the chloroform. as I used DCM, which I'm not sure if it works or not?

 

[ByHyde]

In the first step, you don’t need to use DCM. Wash with sodium bicarbonate until the pH is neutral. Then, distill the mixture at 150°C, monitoring the temperature, and mek separate the distilled part for use in later reactions, discarding the rest. A refrigerator motor will work for the vacuum pump. The hardest part is preventing leaks from the silicone seals.

 

[Labchef]

Byhyde, how do you test for neutrality? Do you test the extracted water wash for neutrality? I get no ph reading when I test the organic layer. How do I test the solution to know when it’s neutral.

 

[TheNut22]

46 g benzald. (~95%) + 36.8 g MEK + 45 g hydrochloric acid (18%). 100°C to 115°C degrees.
Time: 4 hours.

I think I'll use these amounts from now on, because I've never gotten such a large organic phase, and I didn't have to put much more reagents. I was going to put all the reagents first in the same amount as before, but when I put accidentally 45 g of hydrochloric acid, even though I had to put the same 30 g. So I added more of the other reagents to the mixture as well.

The amount of MEK was proportionally less, because it ran out of it, but it didn't hurt at all, because judging by the size of the organic phase, it was a good thing. I now also heated at slightly higher temperatures. I've tried warming up also in degrees 120-130°C, but after several experiments I ended up with that degree of about 100°C. Lower temperatures reduced yields.

 

[handle]

Is that 45g of 18% Hydrochloric acid?

 

[TheNut22]

Yes it is.

 

[Osmosis Vanderwaal]

and mek weighs 0.8g ml soooo 37.85ml 36.8g mek= 46MLand 46g of benzaldehyde is 48.02ml. I gotmtonget the boy on the bus, then I'll be back to finish this math problem. I'm just doing it for practice as I need to improve my chemistry math. It's even more daunting when you are switching between volume and weight, it's probably moot too, but I just want to turn it around in my head and look at it because this is probably something I will need in the future

 

[TheNut22]

46 g benzald. (~95% [43 ml]) + 36.8 g MEK (29.4 ml) + 45 g hydrochloric acid (18% [41 ml]). 100°C to 115°C degrees. Time: 4 hours. After washing: About 45 ml of crystal solution.

 

[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]

I measured the amount, that I have now, and it is: 120 grams of acid/base/salt water washed

MPB crystally oil.
I will put is as it is, because I noticed that I get about same amount of acetoxy with my peracetic acid when I just pour it slowly in, and start heating a little bit, and then leave it 12-14 hours to room temp.

 

[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.

 

[Labchef]

TheNuts22, did you react the MPB oil with peracetic acid without distilling it or obtaining the crystalline MPB salt.