p2p from bmk synthesis confirmed?

[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.

 

[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.

 

[UWe9o12jkied91d]

U think so? Separated from what? And what is left if it separated?
BMK has a pretty light aroma, have u compared with smell after reflux?
I'm not saying you don't know how it smells or that I am not wrong, just looking to know

 

[Ortist]

Separated from sodium . Actually I am struggling now with 5449. Tried bunch of methods and so far got 1ml from 10g. Will try phosphoric acid at 110. When I add acid to 5449 it turns to oil very quickly but it is not p2p. Or may be my 5449 is not real 5449

 

[UWe9o12jkied91d]

Fair enough, it may be so.
I can speak for large scale and with 2-3 hour reflux this time but phosphoric and citric both work great. For citric 25kg/20kg 5449.

 

[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.

 

[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.

 

[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

 

[w2x3f5]

110
his photo shows that p2p is partially oxidized due to overheating

 

[K-Cyanide]

What substance do you think you have recognized ?

 

[w2x3f5]

Why should I determine what kind of impurity is formed during overheating? I lowered the temperature and the p2p output went up.
In my method, people on the forum got 90 percent yield of the substance.

 

[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.

 

[crocodile]

This thread became a bit confusing, (due to the way the replies to questions are arranged).
So which temperature is best 135c or 110c?

 

[K-Cyanide]

For the method by @w2x3f5 110C, for the version of @Acab1312 135C

 

[Acab1312]

To solve the confusion, I also don't go to such high temperatures anymore. The yield as well as the purity is increased.

 

[Tweaker]

How come my oily layer goes to the bottom?

 

[UWe9o12jkied91d]

Phenylacetone is heavier than water(by a vey little) , so it will sink normally, this can give you some indication but it can vary depending on dissolved things in water, water amount used every time etc. so it's not a good way to tell which is your product or if reaction is complete or what have you

 

[masterpell]

After adding acid, the pH is less than 3, and the RM color turns green. Very strange, I wonder if I did it right?

 

[G.Patton]

Hello. Please, describe clearly your step-by-step procedure if you wanna get help. Are you sure that you used BMK glycidic acid sodium salt?

P.S. There is BB Forum tutorial with the approved guide and video

Phenylacetone (P2P) synthesis via BMK ethyl glycidate

This phenylacetone (P2P) synthesis approach is a simple way how to get phenylacetone from BMK ethyl glycidate and its synthesis from benzaldehyde. PMK ethyl glycidate can be hydrolyzed into P2P. This reaction isn't sensitive to water like BMK methyl glycidate synthesis. There is such advantage...

bbgate.com

 

[masterpell]

I am not sure if it is the real CAS:5449-12-7. My steps are to heat purified water to 40-50 degrees Celsius, add bmk powder 1:1 to the purified water and stir, then add 38% dilute hydrochloric acid. The RM solution immediately turned green and formed a large amount of foam. As the reaction gradually cooled down, it began to form layers, with the top layer being a layer of black oil. The lower layer is clear water liquid

 

[masterpell]

So your expert opinion and suggestion is that at the melting point of the substance, it should be carried out at about 133 degrees Celsius, and use a condenser tube to reflux for several hours, right?

This substance is always in a very dirty state at 70-90 degrees Celsius. As shown in the picture, it looks like a cup of coffee. When layered, it looks like a dark brown oily substance with an unpleasant smell.