P2P synthesis from BMK Glycidic Acid (sodium salt) - modified version

[Heisenblack]

Introduction

This is the modified preparation of P2P CAS 103-79-7 made using BMK Glycidic Acid ( sodium salt ) CAS 5449-12-7 with Phosphoric Acid 85% CAS 7664-38-2

Equipment and glassware:

• 1000 ml 3-neck Round bottom flask
• Distillation adapter
• Condenser with a receiving flask
• Dropping funnel
• Thermometer to control liquid temperature
• Hot plate or Magnetic stirrer (do not place the flask
• Boiling stones (pieces of broken porous ceramics)

Set-up:

Use a 3-neck Round bottom flask - on one neck you put the thermometer to measure the temperature of the liquid; on the second neck you put the distillation adapter with a condenser connected to the receiving flask, and on the third neck you put the dropping funnel.

Instruction:

For 50 gr batch

1. Pour 100 - 150 ml of Phosphoric acid into the flask, add boiling stones (3 - 4 pea size porous ceramic) and heat to 110 °C
2. Dissolve the BMK sodium salt in boiling water (optimally 12 ml of water per 1 g of BMK sodium salt) and add to the dropping funnel
3. Slowly add the dissolved solution into the acid drop by drop

The reaction will begin immediately, and you will distil pure p2p into the receiving flask. The distillate will be milky water (similar to steam distillation). The reaction is complete once your distillate becomes clear water. The p2p should be extracted using 3 x 30 ml DCM (any other solvent will probably work), drying over molecular sieves/silica gel and evaporating the solvent.

When done correctly, the yield will be 80%+.

Important notes:

• Do not place the flask directly on the hotplate, use tripod stand
• Boiling stones are very important if you do not use a stirrer
• The addition of dissolved glycidic acid should be slow (drop by drop using dropping funnel) for good yield - be patient
• The temperature should be maintained at 110 °C, not higher

I have done this reaction using 20 gr BMK sodium salt - yield 12 ml (88%) and 50 gr - yield 28 ml (83.5%).

The method was done under the instruction and guidance of @w2x3f5 , all credit goes to him.

 

[Heisenblack]

@G.Patton

 

[btcboss2022]

Interesting process but for 1000gr of BMK theorically 12 L of water should be added drop by drop seems quite slow and tedious.
I'm not sure if Its a good process for Big scale.

 

[Heisenblack]

The distillation of p2p begins immediately as the drops are added, by the time you finish adding, the reaction is complete and you have pure product in the receiving flask. It takes about 1 hour

I agree it might not be economical for big scale since it requires a lot of water and excess acid.

 

[G.Patton]

Hello, do you mean Claisen adapter?

What concentration of the acid have you used? Why have you added so much acid? 100 - 150 ml is 3.5 - 5.2 fold excess.

Why don't you added the acid into glycidate aqueous solution and did in vice versa? I guess, It takes a lot of time.

 

[Heisenblack]

Yes Claisen adapter.

I used 100 ml for 50 gr batch, excess acid is to prevent the formation of layers in the flask and to make the reaction go on immediately, this minimizes the formation of byproducts. The amount of acid can still be optimized to make it economical. When I had less acid, I could see the brown glycidate layer in the flask. I forgot to mention the pH of p2p in the receiving flask was 5.5 - 6.

The process takes about 1 hour to complete.

 

[G.Patton]

I think it has no sense. An excess of the acid (too big) will not change the reaction way.

Have you tried a bigger than 50g scale?

Thank you for your experience report here!

 

[Heisenblack]

I am going to make 100 gr scale, then 150 gr, then maybe 200 gr.

With 50 gr scale, I am going make it couple of times while varying the amount of acid and water to find the optimal amount to add. This will be my project now, I will keep updating the thread with the results I get.

 

[w2x3f5]

scale is not important. the reaction itself occurs continuously in a small volume of the substance, there is no difference of 20-1000 grams, since the p2p product is continuously isolated from the reaction mass.

 

[w2x3f5]

85% standard acid

 

[G.Patton]

It is an obvious thing

 

[G.Patton]

I ask because hardly imagine large scale of dripping the reaction solution to acid. It would take a lot of time. I guess, you have to use couple drip funnels or something different.

 

[w2x3f5]

If the scale is large, then there is no problem to drip with a peristaltic pump (or any other suitable pump), all depending on the heating power and the heat capacity of the acid.

 

[w2x3f5]

I will answer all in one post.
Acids are used a lot for the inertness of the temperature when an aqueous solution of glycidate is added dropwise, the reaction took place immediately and the free ketone was immediately distilled with steam. That is, the initial reaction temperature is about 110 degrees, when an aqueous solution of glycidate is added dropwise, it drops to 108 degrees.
Also, an excess of acid makes the mixture homogeneous; in such a mixture, hydrolysis occurs instantly.
The acid can be optimized based on the fact that we need to dissolve sodium phosphates, make the mixture homogeneous and sufficiently heat-resistant.
12 ml of water per gram of glycidate is needed for the steam distillation of p2p, my research has given that 10-11 ml of water is needed to distill 1 ml of p2p, that is, I provided some margin for complete isolation of the ketone from the reaction mass.

For this hydrolysis, it is better to use glycidate rather than sodium salt, in which case much less acid can be used, and there is also no consumption of acid for the formation of sodium phosphate.

This technique gives the maximum yield, plus all the ketone is steam distilled and can be used without purification.
Set the dropping at a speed so that the temperature of the mixture does not fall below 105 degrees, that is, everything goes almost automatically, the more acid and the more powerful the heating, the higher the rate of dropping. I have a technique for scaling, but it is purely commercial (conversion from 5 to 500 kg of glycidate per reaction), so it will not be published.

 

[qwe111]

Good morning sir.
I know nothing about chemistry.
I have a question. Distill immediately after addition. Was dehydroxylation completed in such a short period of time?
When I use phosphoric acid to reflux 5449, when I add phosphoric acid to the 5449 solution, it immediately separates into an oil layer. But he was not finished and needed to reflow for more than 4 hours.
Is the final product using your approach P2P?
What is the profit rate for this P2P to convert sodium borohydride into methamphetamine?

 

[w2x3f5]

I have distillation with water vapor P2P from boiling mixture of glycidate \ phosphoric acid \ water, or by microwave irradiation until the excretion of carbon dioxide is stopped and then distillation with steam. If you have a separation, then you can use more acid / water, I had this because of the loss of sodium phosphates, but usually I worked with free glycidate. Amin's crop is 70+ percent of the theory (it may be higher if you observe the conditions and get the maximum output of the intermediate Imin), with recovery amination in sodium borhydrid, from the p2P.

 

[chef learner]

Hello, I would like to ask about what you said about using glycidyl salt instead of sodium salt. How can you tell the difference between these two salts? Is CAS the same?

 

[w2x3f5]

I'm also currently developing syntheses for:
one-step reaction from valerophenone to final aminoketone, preliminary yield 70-75 percent, series of experiments needed for optimization.
one-step synthesis from p2p to meth, there are developments, but there is no time to check.
one-step synthesis from propiophenone to aminoketone, 50/50 prospects, needs to be tested.
if you are ready to spend a little of your time and reagents, write me in private messages. I will give out experiments, everything is free, in pursuit of knowledge)

 

[metux]

How to distill glicidate(oil) without exploding flask?add stones or i need mixer,?its just bubling and gassing to strong,exploding bubles,it takes ages to distill.

 

[Heisenblack]

You need to explain step by step what you have done

 

[w2x3f5]

why distill glycidate?

 

[metux]

Its best with stainles steel i think.

 

[w2x3f5]

also hydrolysis works with cas 20320-59-6

 

[metux]

Am already hidrolized bmk oil,and its floats on surface,i folow G.patton,extraction method,100gr glycidade 20gram naoh with 300mil water,affer reflux 1h,and cool to room temp,added hcl about 28% 200ml,then refluxed again,for 3hours,with mixing,after finish all,i get brown oil,and white salt on the botton,i try to disstill without extraction,becose i doint like messing with extraction,it worked for a while,i can't distill all stuff from the reaction flask becose its starts exploding,with big bubbles,and gasses,my termometer cracked,and stuff almost not exploded into face.

 

[metux]

5449-12-7

 

[metux]

Its a bich to work with,yield is shit also for my.

 

[w2x3f5]

use boiling stones (pieces of porous pottery) and your mixture will boil much more evenly if it is not thick
steam distillation won't save you from solvent extraction of the ketone...