Insoluble Leftovers from re-converting

[Paradoxon]

I converted some DMT-freebase to fumarate and back as a cleaning procedure. After recrystallization of this re-converted freebase in warm heptane, i found some white residues on the bottom of the glas, which just wouldn´t dissolve (i added more heptane than enough). Is it possible, that those insoluble residues are maybe fumaric-acid or sodium carbonat?

 

[Paradoxon]

Well, the residues were soluble in distilled water and the pH was about 10. So i assume the leftovers were sodium carbonat. Anyway, did someone else noticed the same thing?

 

[endlessness]

How did you convert to freebase? Can you describe your exact steps?

Definitely sounds like sodium carbonate excess... But this can be eliminated depending on how you do the conversion.

 

[Paradoxon]

I followed the Type 1 procedure from the Fumarates to Freebase Conversion TEK, which was kindly posted by you, endlessness, as i assume. I definitely added some excess sodium carbonat water solution (maybe 2-3 ml) to the DMT-fumarate-water, since i did it the first time and was unsure about how "no more clouding" looks like... I´m sure i could have done it more slowly.

However, I don´t mind recrystallizing in naptha/heptane. The possibilty of cleaning the spice, while it is a fumarate-salt, is intriguing to me though Will try that soon.