Synthesis of Amphetamine from P2NP via SnCl2 and Zn

[Bigballen]

How much desired acid to add at the end?

 

[blacky2340]

Pour 10ml acetone onto 1ml concentrated 97%+ sulfuric acid 10:1 ratio. Use pipette or syringe to drop the solution slowly until pH 5.5 is reached. If overacidified, add more freebase, if way overacidified and turns into liquid then to a/b and recryistalize.

 

[yuiopjkl]

You can use a non-polar solvent (ether, benzene, toluene)

 

[TucoSalamanca.]

How many hours will we cool the sodium hydroxide solution?

 

[yuiopjkl]

Until it cools to room temperature

 

[mithyl2]

how much anhydrous magnesium sulfate should be added at the stage when drying the ethyl acetate and just before adding the glacial acetic acid?

 

[TucoSalamanca.]

I think you can stop adding magnesium sulphate when you realise that it is completely absorbed.

 

[mithyl2]

But what is an easy way to see that?

 

[TucoSalamanca.]

add magnesium sulphate, if it settles to the bottom you know it is enough, then close the lid, leave for 1 hour, then strain

 

[mithyl2]

At the stage before you add the DCM, do you separate the solution at all? (Because at the point just before you add the DCM you have the organic layer and the aqueous layer). Or do you add the DCM to the solution without the 2 layers being separated?

I just tried to separate the 2 layers and add DCM to the aqueous layer to start with, and then a lot of precipitate just came out of nowhere. I separated the DCM from it, dried it, added the anhydrous acetone, and then the acid, but absolutely nothing precipitated.

I also added the DCM to the other (organic layer I think, which must be ethyl acetate) and the DCM appeared to dissolve into it and didn't appear to form any layer. Is this normal? (Although here I added a small amount of DCM to a much larger amount of the solution.)

 

[TucoSalamanca.]

You separate 3 times with ethyl acetate before dcm, i.e. ethyl acetate is used instead of dcm in the 1st extraction and dcm in the 2nd extraction.

 

[mithyl2]

and the ethyl acetate and dcm extracts are combined just before drying them, and then doing precipitation with acid?

 

[yuiopjkl]

I don't understand your problem
I think there is no difference.
The pH of the mixture must be 11-12.
The DCM layer is the bottom layer.
I think it is better to evaporate the DCM and then add acetone to the amphetamine base.
Why do you still have the ethyl acetate and oxime solution?!!
Yes, there will be no layers because DCM is miscible with ethyl acetate.
No!

 

[mithyl2]

At step 10, when you are you filtering the mixture, do you want the NaOH layer separated from the ethyl acetate layer? Then you extract the oxime from the NaOH solution with DCM?

Because I thought the filtering at step 10 was only to get rid of the zinc, so you would still be left with the ethyl acetate layer and the NaOH layer, then you add DCM to these 2 layers, giving you 3 layers in total.

 

[mithyl2]

Could someone also advise on if it's ok to use the hemihydrate form of the tin (II) chloride instead of the dihydrate?

 

[August]

Hello, thanks a lot for posting this. I have a question, I am at the stage of basifying the solution after adding the hydrochloric acid in cold water ( i got this backwards and added the reaction solution to the cold water + hcl instead of the other way round, maybe thats why im having this problem ). After adding the 50% naoh solution and basifying to pH > 10, there is a lot of precipitate however it is floating on top of the solution instead of settling, making it very hard to extract with ethyl acetate. Is this a cause for concern or do i perhaps just need to wait until it settles to the bottom?

 

[Madeinkorea]

Very interesting synthesis!
I have a question about the part when we first add NaOH to the mixture (5th step), after the NaOH solution was added to the mixture, do we add ethyl-acetate to the mixture so we can separate the Oxime from the acetone, or am I getting something wrong.

 

[yuiopjkl]

Yes, Ethyl acetate is used to extract oxime from the mixture

 

[TucoSalamanca.]

1st stage 200ml water and 200gr sodium carbonate 2nd stage 100ml water 50gr sodium carbonate can be used?

 

[yuiopjkl]

Yes, add until you reach pH 11-12

 

[TucoSalamanca.]

what can I use instead of dcm

 

[yuiopjkl]

ether

 

[TucoSalamanca.]

what can be used instead of magnesium sulphate

 

[mithyl2]

magnesium sulfate is very easy to get worldwide I think. Are you having problems getting it?

and you need to make it completely dry before using it. I put mine in a microwave.

 

[yuiopjkl]

Sodium sulfate anhydrous. Na2SO4