p2p from bmk synthesis confirmed?

[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.

 

[Mo0odi]

Cool

 

[Sig]

@jasper

 

[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

 

[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

 

[G.Patton]

Check its melting point, it's not look like P2P

 

[masterpell]

After heating to 90 degrees Celsius, the color is still the same. Is there something wrong with the steps? Or is this powder not 5447?

 

[G.Patton]

About what color are you talking about? Do you understand what is melting point? Melting point determination
I found that this substance has Melting Point 133-136 °C

 

[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.

 

[OrgUnikum]

BMK 5449 is glycidic acid sodium salt. Transforming this to P2P proceeds through the following steps:
- the sodium is removed from the glycidic acid by adding an equimolar amount of acid, means one molecule of BMK to one molecule of acid, this would be for example 100 ml HCl 36% for 200 g 5449.
- The glycidic acid is decarboxylated, CO2 is split off. Thats a thermal reaction, it works by heating. Some strong acid present helps though. But thats catalytic so only very little acid is actually needed it also does not get used up, in difference to the part for removing sodium, this forms the sodium salt, NaCl with HCl.
- The epoxide which is exposed by the decarboxylation re-arranges itself to the Ketone, to P2P. This is also done by heat, but you do not have to worry this happens automatically directly after the CO2 is split off so one can look at it as one step.

So for 200 g BMK 5449 it is enough to use 115 gram of HCl 36%, but it is a good idea to use a lot of water. 1 liter for 200 g is ok. Also NaCl should be added, 25 g per 100 ml water or more. Dishwasher regeneration salt is pure NaCl and very cheap. Thats to make the water denser, heavier then P2P as you want it to come out of solution and the water is alreeady heavier so you end up with an emulsion and thats not good.
Now I wrote the reaction is due to heat. But only little is needed, you can see the CO2 coming out as you see it foaming and that happens already at 50 to 70 °C max. When there is no more CO2 formed the reaction is over. All this heating to reflux, boiling for hours is completely unnecessary. Try it. No more bubbles/foaming at 70 °C max - done. Nothing but killing your P2P happens after this.
Now you have the P2P on top so use toluene or ethylacetate/naphta for extraction.
The BMK must be fine powder, no hard lumps. Easiest way is to yank it through an elctric coffee grinder together with some of the coarse NaCl which is added anyways. You can grind this directly into the stirred, COLD, water/HCl mix, when all is in temperature will have risen to almost 40 °C so you just go on and heat and you see soon the foaming. Heat a little longer after no more foaming takes place, let cool down and extract. The water is needed to have the P2P more diluted. With not enough space it will condense with itself, polymerize, the less water the more P2P will be lost this way. You get 125 to 130 g from 200 g BMK 5449 this way and it is already clean (the acid must be washed out though) and good enough for the next reaction.

It can be done in a plastic bucket if the bucket is heated on a waterbath. I mean real bucket, like the black ones they use for mortar at building sites, not the crap from the dollar store. You can drill a hole near the bottom into those and put in a faucet. PP, polypropylene is the material of choice here. Such come extremely handy not only here.

And yes, some time ago I used a more complicated method (with good success) but live and learn and try to progress as stagnation is death.

All the best. You got the explanation what happens in the reaction and the method which was developed from this knowledge and with lots of practical testing.

Take it or leave it, up to you alone, I will not discuss this topic anymore as for me thats finally solved and I have moved on to new things already.

 

[damakemi]

thank you very much for sharing this information i ver much appreciate it. Can you explain how to wash the mixture properly and how to get the ph way up?

 

[Sig]

finally someone who does it like me.

 

[edy's]

Geniaal

 

[Acab1312]

Thank you very much, I tried it and it worked very well. I had the problem the first time that the finished p2p became hard as stone after cooling. On the second and third attempt it worked great.

 

[Tweaker]

How do you wash the acid out?

 

[OrgUnikum]

The separated P2P is washed several times with plain water in a separation funnel, say P2P (with or without organic solvent) and water together, shake like mad and not only once, then let sit and separate the two layers. If it does not separate (P2P bottom) then add half of the water again as brine (saturated salt solution) and try again. The added salt will make the water layer, now heavier separate at the bottom. Do this several times p2P is virtually insoluble in water - no losses. At the end you use pure brine, shake once and let sit for several hours. The brine will suck all water which might be dispersed in the P2P out of it but this takes time.
Now you should be left with absolutely clear P2P free from acid and other contaminants.

 

[damakemi]

thanks that should be easy, is it necessary to make the ph neutral for making N-form?

 

[Tweaker]

Thank you. I think this is why my yield was destroyed the first run. I left the p2p as is and was very acidic.

 

[masterpell]

This time I added the alkaline solution, and then started stirring until the pH was greater than 10, and then the solution began to change to a coffee-like turbidity. Then I added acid, the pH was less than 3, and the layers began to separate. as the picture shows

 

[OrgUnikum]

Read the bloody description of the process for BMK 5449 and do as described. You used the method for PMK ethyl glycidate, thats all.

 

[OrgUnikum]

Read the bloody description of the process for BMK 5449 and do as described. You used the method for PMK ethyl glycidate, thats all.

 

[OrgUnikum]

The official guide lacks to mention the needed addition of water before adding acid and the addition of a lot of table salt. The density of water and P2P is so close that already the salt formed by the reaction is enough to make the water layer so heavy that you have an emulsion in the end, More salt prevents this and P2P is collected at top as its now less dense then the saltwater below. Also the permanent contact of P2P in an emulsion causes polymerisation and losses.

Now those people have obviously poured the concentrated acid onto the BMK powder directly and thats not gonna work out well.

@Patton I suggest to amend the official guide for clarity

 

[masterpell]

I seem to understand! I don't seem to understand. Am I too stupid? Are there multiple types of BMK? For example, 5447, do different BMK types have different melting points?

 

[G.Patton]

It is a wise recommendation, I will. Thank you.