With MDMA i don´t know, but Meth HCl disolve completly in DCM  .
May be not.
Hexane is Fine but all must be cold before add the solvent.

Comments appreciated and duly noted  thank you

Looked at the pdf.

Are you saying toluene would be best?

"The mixture was refluxed for 2 h.
After cooling to room temperature, an 8.3 M NaOH solution (16.0
mL, 0.13 mmol) was slowly added, and the crude methamphetamine
base extracted with toluene (3 × 20 mL). The combined
organic layers were dried over MgSO4, and the volatiles removed
in vacuo to reveal the crude methamphetamine base as a brown
oil."

Really useful info. ty..

From one of the links on there im reading this which I have read before.

http://www.erowid.org/archive/rhodium/chemistry/mdma.impurity.study.html

I have been confused by this write up more than any of the others.

Majority of papers I read some way or another always lead to MD-P2P. Then the conversion of this to MDMA hence my original question.

With the particular paper mentioned they talk about MD-PBP (note the B not P) and also PMK

PMK confuses me cause some say its actually (MD-P2P.) some say its a new way of getting to MDMA. Im also confused if this paper has typoed MD-P2P for MD-PBP

What Lugh said.
 Most non polar solvents will be ok for extracting freebase. DCM also. Toluene, along with diethyl ether are always my preferred freebase extraction solvents. Toluene beacuse it has good solvating power and is "self drying" (azeotropic distillation) and Et2O because of its solvating power and its low b.p.
I usually refrain from DCM in extractions if I can because of its tendency to create emulsions.

But he is talking about reductive amination Al/Hg i think...if one try to extract the reaction mix with DCM here will fail almost sure,or will be a painfull workout...it will finish with a freak  emulsion sure,...because all that crap,powdered alumminium,...will tend to sink to the bottom with the DCM,so clean it afterwards will be a pain.
   Yeah too,the mix resulting from Al/HG reduction have way more density than water alone,it´s a thick mass...and on that situations,i allways got a freaking emulsion using DCM as extracting solvent.,..that works fine only extracting on light acid solutions ,like the one resulting on the benzo wacker.So if you can´t use toluene or xylene,use anything that will go up on the separation,You can allways experiment with few ml of final mix reaction and test extracting  with DCM to see how it works,but sure use DCM here must be the last alternative i think.
   DCM good for Benzowacker,but not at all on the AL/HG.
  I worked  a lot Al/Hg both with Xylene(on the begining) and Toluene,and are exactly the same.Pick up the one it´s easier and cheaper to get...Anyway,both will work fine without emulsions if you only stirr the mix carefully long time without big hard shaking.
  Seems xylene tends to not separate so quickly,it mixs  better with the reaction mix,so possibly extracction can be more efficient,but nothing that you can´t do extracting with toulene with pacient....Like said,i prefer toluene because avalibility,price(way less than xylene) and easy work...Allways a 5 litre bottle on room´s corner it´s a must,...you can extract with it almost every reaction we talk about,and re-use after extracted the goods and clean it with water washes....I used to have labelled recicled toluene as "benzo recicled" and "al/hg recicled" , and use each bottle to extract each reaction.. When i think i used it too much,...i bought another 5 liter bottle cheap as hell and have toluene for months.Too,i used to let alone big amounts of used toluene distilling along an afternoom when not to much to do, to get liters of almost fresh again toluene to use....only reserve it, and distill all on one run.
   I only used DCM to extract acid solutions,and on that situations,worked fine allways....When density of mix it´s only little bigger than plain water,then begins problems with DCM.

DCM is very prone to create emulsions, impossible to separate. Ether is much better, but the solubility in water is too large.