How much Xylene after A/B of freebase necessary?

[methlab]

Hi! I just want to know, how much Xylene i should use for reextraction. MM uses 500ml Xylene for extracting freebase out of the Al/Hg sludge. Then I did an A/B to clean up the freebasesolution (500ml). I used about 200ml 10% HCl which i basifyed with a little bit NaOH (until brought to PH 12). The solution turned a bit milky white. (OK until now?)
How much Xylene do i now need, to get everything back into the Xylene? Thanx.

[abolt]

8 times the volume of ketone is a good figure. Divide this amount into 3 lots and Do 3 extractions

[Rhodium]

abolt: Are you referring to the initial amount of ketone put into the Al/Hg, or are you mistaking the above question to be one about MDP2P rather than MDMA freebase?

[abolt]

I would assume that methlab is extracting freebase into NP for gassing. Is the triple extraction unnecessary at this point?

[Rhodium]

Definitely not, I just wanted to see if I understood you correctly.

[abacus]

Do it the right way...

Definitely do the A/B wash.  Wash your HCL wash (amine "dissolved" in the acidic aqueous phase) with xylene or toluene and NOT DCM and discard this layer that has the unreacted ketone.

Basify this acidic extraction with NaOH until pH 12 or so and extract MDMA base using DCM, Toluene, or Xylene. 

Repeat until you have enough freebase until you can vacuum distil.

Distilling the freebase is the way to go, anything less is for amatuers.

[methlab]

I think now I know where i have lost half of my product. I did ask this question, because last time i did just one reextraction with just 200ml Xylene. I got about 1/2 of the expected amount. Today i will do it better, will let you know how much i got this time. Thanx.

[methlab]

75-80% is the convertion rate now, this is not bad for me. Don't know how the others get higher yields, but I can live with this result. Maybe i have a cleaning-psychosis and that's why i am loosing something of my product.  

[Xicori]

Definitely do the A/B wash.  Wash your HCL wash (amine "dissolved" in the acidic aqueous phase) with xylene or toluene and NOT DCM and discard this layer that has the unreacted ketone.

wzhy souldn´t one use DCM at this stage? - I think it is much easier to handle, and extracts the non-wanted byproducts & ketone very good.

Its clear that the DCM washes must not be washed down the drain, because chlorinated organics are a bad thing fot the environment... - so redistill & save a lot of money & solvents!