Alpha-PVP synthesis (1-10kg scale). Complete video tutorial.

[Marvin "Popcorn" Sutton]

100g bk,100ml pyrrolidine (~90g) ,400ml EtAc
these are the correct proportions for the AMINATION step
after completion of the reaction add 600ml of water to wash and separate the organic phase
acetone is added before acidification, after the organic layer has been separated from the aqueous layer.

 

[dkemist15021982]

Hi can somebody tell me how i can get rid off an harsh pyrrolidine tast that i have with.my selfmade pvp?

 

[The Silent Chemist]

You need to wash the free base carfully with water first to remove the pyrrolidine, after that then your standard recrystallisation from acetone or ethanol

 

[VamonosPest]

What could i replace pyrrolidine with?

 

[Hank Schrader]

Methylamine. You will get also good product.

 

[Caleb]

Actually the idea was to show (again) that people using substances are being treated llike criminals.
In some places they are even seen worse than child molesters and suicide bombers.
This speaks for itsel.

 

[The Silent Chemist]

Hey all any help would be much appreciated, I had my first attempt at the apvp synthesis today.

During stage 1 halogenation, I followed the procedure excatctly as the video discribes adding the H202 slowly to the reaction vessel that contains the valerophenone and hydrobromic acid, ensuring the temperature did not exceed 60c.

I noticed that the red bromine colour persisted and did not go away after adding 2/3rds of the 43g of H202. I took this as my visual cue to not add any more peroxide.

(I assumed this was because I concentrated my peroxide from 6% to the 37% via boiling off the water under vacuum and I may have over concentrated it a little)

I let the reaction mixture stir for 10mins to ensure that the red colour would not go away. It did not.

shortly after adding 500ml of distilled water to the reaction the bottom bromovalerophenon layer turned from red to milky white.

my guess is I did not add enough peroxide and let the reaction stir long enough. I have discarded it and will try again.

any help would be appreciated

 

[The Silent Chemist]

The distilled water I used was contaminated with Hcl, litmus test showed it was acidic. A second run has now been attempted with no problems with the addition of water, the reaction stay dark red upon first wash with distilled water, a second wash was done with an alkaline solution as what the written instructions request, this second wash did lighten bromovalerphenone colour to a golden yellow.

 

[islandgato]

A-PHP synthesis would be awesome !

 

[ChemKing]

4-bromo-Alfa-pvp.
He carried out the synthesis of this substance. But I ran into a problem - it is very poorly soluble in water. What could be the reason? Synthesis began with 4-brimvalerophenone. He performed bromination, received 4-bromo-alpha-bromvalerophenone. Then he carried out a reaction with pyrrolidine. Then I got the salt using HCl. The final product is very poorly soluble in water. About 10g per 100ml

 

[Batracien]

Hello, I have done the bromination and the amination step but i'm not sure of the proportions I've used in the amination.
How much moles of pyrrolidine is needed for 1 mole of 2-bromovalerophenone, I used 2 moles pyrro for 1 mole bromovalerophenone, but here you all say that the good proprotions are : 100g bk (0.4mole) / 100ml pyrro (1.2mole) so 1/3.
Why it isn't possible to use 1/1 or 1/2, I don't understand why so much excess is needed. And EtOAc just act as a solvent or is the molar ratio of EtOAc important as well ?

 

[The Silent Chemist]

If you read carefully further back in the chat you will see the correct ratios stated, let me know how you go trying to crystallise the A-pvp. An excess is used to ensure all the bromvalerophenone is reacted. I am having difficulty getting it too precipitate out of solution. If you have trouble try distilling the free base under vacuum, ensure all solvents are anhydrous.

 

[Batracien]

I'm going to try evaporate EtOAc (and possible leftover pyrrolidine) in a water bath and OUTSIDE (I don't want to die), and dilute the free base with 0°C acetone (99%), then add hydrochloric acid (23%) until ph = 5 and finally put it in the freezer to filter it, do you think it will work ?

 

[Batracien]

I have an other problem concerning storage, I stored my 2-bromovalerophenone for almost 6months at normal conditions, and it seemed to have 0 effects on it. But what about my freebase/EtOAc, it was first slightly yellow, and now after a week it is orange, I have to store it because I Don't have time to go outside to my improvised forest laboratory for a month. Thank you for your advices and good luck !

 

[w2x3f5]

Evaporate ethylacetate and further fractionally evaporate the base in a vacuum.

 

[mb16]

In stage 4 diasteromeric. It says...

"1. a-PVP HCl 10.0 g, 35.5 mmol is dissolved in minimum volume of distilled water"

A-pvp has a molar mass of 231.33g wouldn't that make 35.5 mmol of a-pvp to be 82.12g and not 10.0g as stated above?

Also it seems a little overkill to use 700ml of hexane and 530ml of DCM to dissolve 10.0g of a-pvp.

Is this supposed to be starting from 100g and not 10.0g, is there a decimal in the wrong place here perhaps?

 

[mb16]

Sorry I mean...

A-pvp has a molar mass of 231.33g wouldn't that make 35.5 mmol of a-pvp to be 8.21g and not 10.0g as stated above?

 

[mb16]

No sorry the molar mass of a-pvp (HCl) is 267.8g which would make 35.5 mmol 9.5g.

 

[getmoneyforlife]

Hi. I have a problem with crystallization. After adding hydrochloric acid, the reaction does not crystallize. When you first start mixing the 2bromovalerophenone with the ethyl acetate and prolidine, it looks like it didn't mix well. The mixture was stirred for 1 hour. The layers have separated and it shouldn't be like that. Only later did I add distilled water and the phases separated, but why does it look so bad at the beginning?
Proportion:
*2bromovalerophenone ~760ml
* ethyl acetate 4L
*pirolidyna 1L
*water distillate 6L
*Aceton 4L
*ACID 36% 200-300ml

 

[w2x3f5]

Add acetone and put in the freezer for a day

 

[getmoneyforlife]

Ok, . But the bigger problem for me is why are the layers separated at the beginning when mixing? I'm not talking about the stage when I add distilled water to separate the layers

 

[getmoneyforlife]

 

[w2x3f5]

The problem is that you wrote 4 liters of ethylacetate and etc in the description, but the photo is an order of magnitude less, and you also did not write your work by steps with your observations. I am not Nostradamus to warn your actions and the synthesis itself. Crystallization turned out as I see.

 

[getmoneyforlife]

I have 2 questions.
Why did this liquid start to separate or not mix?
Why did the solution not turn cloudy during acidification with hydrochloric acid?
I started doing it too quickly after a long break, I lost 1 kg, I made 2 samples of 50 g each, but something is not working out as it should. Efficiency 60% 40ml 2bromovalerophenone 50ml pyrrolidine