p2p from bmk synthesis confirmed?

[crocodile]

I was reading the thread by Tor about the p2p from bmk powder and how he does it which seems pretty simple yet I see that many people still have issues getting a clear oil and or getting a sludge.
Is Tor's method 100% tested and working? (It seems solid so I'm confused why people are still having issues and trying to mess with it?
Here is Tor's synth


"we are going to prepare 1 kg of BMK
take a 5 liter double neck flask
add 500ml boiling water . start with the mixer.
now slowly add 1kg of BMK salt. then add 1 liter of sulfonic acid. now connect the reflux and heat the contents of the flask to max temperature. plus minus 130°c. use a powerful mixer
Let it boil in reflux for 4 hours.
take the top layer and pour it into a measuring cup.
let the bottom layer cool and save for next time. ( we have no chemical waste for this preparation method )

now boil 1 liter of water and add it to the measuring cup. use a hand mixer to mix everything.
After mixing for a few minutes, let the measuring cup cool to room temperature.
remove the top white layer (this is water and waste that we don't need)
the bottom layer is P2P purified and ready to use.

ps: in this preparation we don't have to worry about water remaining in our P2P because water weighs less than P2P"

 

[UWe9o12jkied91d]

For me the trick to not get sludge for cas 5449-12-7 was to dissolve in boiling water to a clear solution, turning off heat and carefully adding h2so4 conc.
This got me instant conversion in acceptable yield, with layers forming immediately, but I still refluxed 30 min to be sure.In contrast when I hurried and did not dissolve my glycidate completly no amount of reflux was able to get the solids to react and had to filter them.
Careful of the splashing when adding acid.

 

[Acab1312]

What was your yield?

 

[UWe9o12jkied91d]

I extracted with solvent right after, did not take measurement and counted as 70% of theory with no problem

 

[Ortist]

With H2SO4 layers separate instantly but that doesn't mean you got P2P. It is just glycidic acid separated. I just stried it and got two layers with no smell.

 

[Ortist]

Have you tried phosphoric route? Do I need to add dry powder straight to hot acid with stirring or powder has to be dissolved in water prior to addition?

 

[UWe9o12jkied91d]

Had ok results with dissolving both in minimal amount of water as well as 1L water/kg. Both ways made warm and followed by acid and refluxed.
Cant tell u how much is minimal compared to 1L/kg.

 

[crocodile]

I think the key is to add 85% phosphoric acid instes of 75% and to reflux for longer than 4 hours.

 

[Acab1312]

For me, the problem was that I didn't get above 120 C° because of the water. As a result, the yields were very low: 1kg (5449-12-7) - 400g/Milky Color (P2P). Now I do it without water only with H3PO4 85% (1 L H3PO4 for 750g 5449-12-7) come since then to the 135 C ° and 60-70% yield without this milk coloring.

 

[crocodile]

How long do you reflux it for?

 

[Acab1312]

From where the temperature has reached 135°, 4 hours. It is important to say that I work with an overhead stirrer! because due to the lack of water, very little of the BMK 5449-12-7 dissolves and settles to the bottom.

 

[crocodile]

Ah great fantastic. Cause there are a lot of versions out there and most seem inefficient to me.
Do you steam distill it or just dlpurify it with a simple distillation?

 

[Acab1312]

Hello, I do not distill the product, I only clean it with dh20

 

[K-Cyanide]

@Acab1312 i´ll give your version of the synthesis a try. One question: How strong is the stirring during the 4h reflux ? Do you stir at all? (no stirring with boiling stones). Thank you.

 

[Acab1312]

Hello yes I use an overhead stirrer with high speed just enough so that it does not splash in the piston when stirring the RM

 

[K-Cyanide]

Now a run with the input from @Acab1312 (all credit goes to him) was carried out and the results were quite decent.

2000ml 85% phosporic acid were heated to about 65°C.1500g BMK 5449-12 were added in small portions and stirring. The reaction mixture was heated to 135°C and refluxed for 4 hours.
The layers were separated and the aqueous/phosporic acid layer extracted with DCM. (funny to see that the DCM layer is above, due to the high density of phosporic acid). The combined extracts were washed with water, brine and saturated bicarb solution to get the pH to neutral.

After drying over anhydrous sodium sulfate, the solvent was evaporated under regular pressure.
818 ml (813g) golden brown crude P2P was obtained. Yield : 80,93%

The crude P2P was distilled under reduced pressure to give 656ml (652g) pale yellow, pure 1-phenyl 2-propanone aka P2P, phenylacetone. Yield: 64,90%

The lovely flowery smell of pure P2P is just marvelous.

 

[crocodile]

That looks fantastic.
Question, why not distill the dcm under vacuum at a slightly higher temp that way it also removes the water and eliminates the need to use a dissicant afterwards?

 

[rothschild33]

By layers separated and extracted with DCM, did you mean wait for the layers to separate and add DCM to the entire RM or only add DCM to the milky (phosphoric acid) layer and combine this with the dark layer? I get more dirty p2p from the darker layer but the yield is great so far though.

 

[K-Cyanide]

The DCM is added to the lower, milky layer only. The layers are separated with a separatory funnel. Regarding temperature 110 C you can use with the version of @w2x3f5, here it would last very long to finish the reaction. I do not have access to a HPLC/MS/UVS so I cannot check exactly the purity. Analyzing a substance by looking at a low resolution picture is definitely not a generally accepted method of analytic chemistry.

 

[w2x3f5]

My first experiments were with temperatures above 110, and a solution of glycidate in acid changes color from yellow/orange to brown when overheated and yield drops. My conclusion is based on my experience in this hydrolysis, photo quality is of secondary importance. So the yield of a substance after distillation gives an exhaustive answer.

 

[w2x3f5]

too high temperature

 

[rothschild33]

Do you have a suggested temp range?

 

[rothschild33]

Is this the steam distillation method? I find that route harder to scale up in terms of time

 

[w2x3f5]

In this context, we are talking about the temperature regime of the mixture. Moreover, in a microwave at 60-80 degrees, the decarboxylation reaction goes like a volcano.

 

[damakemi]

Thnx man really love this method. Can you give an explanation how you wash your p2p and bring the ph to neutral? would like to see the ratios

 

[skanderbeg]

That's an insanely high yield for 5449 bmk good job will try. I usually get around 40-50% from HCL route.

 

[skanderbeg]

Just did it, yielded about 70% of the glycidate used.

 

[K-Cyanide]

You can distill the DCM as well, no doubt. I would not leave the water in the P2P before vacuum distillation for the following reason. Looking at the water molecule and its molecular weight, water has an extremely high boiling point. And moreover the enthalpy of evaporation requires additional amount of energy. This energy will also force P2P to evaporate, though in very small amounts. So why should I do it, when drying with a drying agent is a simple job to do.

 

[crocodile]

True but I'm thinking it would be simpler to distill it under vacuum for 2 reasons.
1-bmk is cheap and easy to obtain.
2-the amount of p2p that will come over is negligible and you are going to reuse the same dcm again so the p2p will be recuperated in the next round.

So basically it would save some time cause all you have to do is change receiving flask and not play around with dissicant.

 

[K-Cyanide]

I prefer to conduct these steps separately and have only the desired product left for the final vacuum distillation.