Can FASA be used for de-fatting?

[blue.magic]

I like doing A/B extraction with heated mother liquor since it pulls much more actives more quickly. Unfortunately, it also pulls plant oils even with very slight heating.

I was thinking about de-fatting the extract by converting it to fumarate, wash with acetone (the de-fatting step), extract with water (removes excess fumaric acid) and finaly freebase with sodium carbonate, water and acetone. Or simply via the full mini-A/B route by dissolving the cleaned up DMT fumarate in water, base and extract with nonpolar solvent.

The idea behind this is that plant oils are not forming salts and therefore can be removed from salted DMT with NPS. Maybe DCM or purely nonpolar solvent would work even better on DMT fumarate as DCM can be evaporated easily even at ambient condition or in vacuo, speeding up the process. Unfortunately I cannot find DMT.fum solubility data for DCM.

Do you think FASA route on extracted DMT is viable to make whiter crystals? I have bad experiences with simple recrystallization as the fats usually deposit on the bottom of the container anyway.

 

[Nitegazer]

If you're starting with MHRB, using a more selective solvent like naphtha produces very clean fumarate. It works with FASI, but I have not experimented with FASA yet. Note that Naphtha needs to be heated to about 50c to facilitate the process. [Note: heating is not necessary-- read posts further down]

If you want to clean it further, I'd recommend you re-dissolve and filter through cotton or even activated charcoal before basifying. At least for me, making a carbonate paste results in more yield loss. It may be due to my technique, but I find that pulls from paste are less efficient than pulls from water.

 

[endlessness]

blue.magic, You dont need to defat when doing FASA/FASI, "fats" arent precipitating with fumarates in the first place so you can already get a reasonably pure product that way. If you added the FASA/FASI too fast then the precipitated crystals dont look so clean (though analytically speaking they are still pretty pure), so you can always re-base, redissolve and reprecipitate. Washing the fumarates will get them cleaner, yes, you dont have to wash with non-polar, you can wash with acetone or IPA too, as long as they are cold/dry, and with those washes it cleans even more than with non polar since they are less selective.

Nitegazer, I never tested myself but I seem to remember reading someone (maybe infundibulum ?) saw precipitation of fumaric acid with FASA on clean naphtha, meaning when doing it with alkaloid-laden naphtha there would be excess fumaric acid contaminant in final product. That being said, I havent experimented with this myself, and I cant remember if others double checked it.. Did you try mixing FASI with clean naphtha to see if the fumaric acid stays in solution or if it precips? Might be worth doing this test before using FASI/FASA on naphtha to make sure you're gonna get clean results.

 

[Loveall]

That first acetone wash sould remove any unwanted fumaric that precipitates with the fumarate.

For what it's worth, I have tested virgin xylene by adding a FASA, and a small amount of precipitate formed (I added quite a bit of FASA about 25% of the initial xylene volume).

 

[blue.magic]

blue.magic, You dont need to defat when doing FASA/FASI, "fats" arent precipitating with fumarates in the first place so you can already get a reasonably pure product that way.

Yes that's the reason for using FASA for defat. The target product is still DMT freebase but going via the FASA route as seem to effectively strip off plant oils better than recrystallization or mini-A/B.

Thinking about it, maybe doing mini-A/B (backsalt, base, pull with NPS) will be still easier though since fumaric acid is poorly soluble in water and acetone and it takes quite some effort to form DMT fumarate than use different acid and backsalt from NPS. It seems only negligible amount of plant oils will move to the water layer.

I preferred FASA over mini-A/B for defat as mini-A/B has a risk of losing too much product by moving it between layers.

That first acetone wash sould remove any unwanted fumaric that precipitates with the fumarate.

I usually do three or four acetone washes, with lots of mixing, but there is a small amount of fumaric acid present. The taste of such DMT.fumarate is sour. I dissolved the product in water and a small amount of fumaric acid stayed undissolved (maybe 10 mg or so, not very much).

 

[Nitegazer]

Nitegazer, I never tested myself but I seem to remember reading someone (maybe infundibulum ?) saw precipitation of fumaric acid with FASA on clean naphtha, meaning when doing it with alkaloid-laden naphtha there would be excess fumaric acid contaminant in final product. That being said, I havent experimented with this myself, and I cant remember if others double checked it.. Did you try mixing FASI with clean naphtha to see if the fumaric acid stays in solution or if it precips? Might be worth doing this test before using FASI/FASA on naphtha to make sure you're gonna get clean results.

I conducted the experiment here: FASI in Clean Naphtha Does Not Precipitate

The key is to 'dose' the naphtha with IPA prior to adding the FASI. HEATING IS NOT NECESSARY

I couldn't find your reference to precipitating fumaric acid, though I did see in the Wiki a reference to in in relation to FASA. It could be that IPA is a better solvent than acetone in naphtha, or that dosing with acetone was not tried-- I'm not sure.

 

[blue.magic]

Thanks, Nitegazer.

I think I will use a water soluble acid such as 1% sulfuric, solely because of least fumes and odour.

I will try the method from an1cca's mescaline extraction, i.e. putting little bit of nitrazine in the sep. funnel and add dilute acid dropwise until the water pH will stay neutral.

The FASA was tempting since one byproduct would be DMT fumarate, which I also utilize and won't need to make it separately.

But in the end I will probably go via the mini-A/B route (the aqueous layer will be obtained with backsalting, instead dissolving the product in acidic water).

 

[Loveall]

blue.magic, I'm surprised the acetone washes do not remove excess fumaric acid. Do you add enough actetone? You need about a ml for every 6mg of excess fumaric acid. If you evap the acetone you can see how much it picked up.

I've done a test where before I do an acetone clean, I dissolve a small amount of FASA product in water and get a low pH (). Then after a single fresh acetone wash and dry, the same water sample test gives a roughly neutral pH (>5). Based on other tests with pure funaric acid and water, I took this as evidence that acetone works well to te remove excess fumaric acid. Am I wrong?

 

[blue.magic]

blue.magic, I'm surprised the acetone washes do not remove excess fumaric acid. Do you add enough actetone? You need about a ml for every 6mg of excess fumaric acid. If you evap the acetone you can see how much it picked up.

I've done a test where before I do an acetone clean, I dissolve a small amount of FASA product in water and get a low pH (). Then after a single fresh acetone wash and dry, the same water sample test gives a roughly neutral pH (>5). Based on other tests with pure funaric acid and water, I took this as evidenve that acetone works well to te remove excess fumaric acid. Am I wrong?

I did three cold acetone washes (25 ml each).

There was very little fumaric acid left in the water (the amount was like dozen grains of salt) but now the cleaned DMT fumarate is bitter to taste, no longer sour.

For some reason the fumaric acid I have takes a lot of time and mixing to dissolve even small amount in fresh acetone. I don't know if this is normal. It takes me about 10 minutes just to prepare FASA, it's mixing and mixing, quite an elbow grease.

I will do the pH test next time, thanks for suggesting this.

 

[Loveall]

I keep dry acetone in the garage and it has been pretty warm. I also take my time with the acetone wash and shake it a few times over a day or so. Maybe that makes a difference. I'll evap the acetone next time to see how much fumaric it picks up after 1 and 2 washes. I feel like someone must have done this already in the FASA threads though...

 

[blue.magic]

I keep dry acetone in the garage and it has been pretty warm. I also take my time with the acetone wash and shake it a few times over a day or so. Maybe that makes a difference. I'll evap the acetone next time to see how much fumaric it picks up after 1 and 2 washes. I feel like someone must have done this already in the FASA threads though...

Yes I keep the acetone over calcium chloride in a small reagent bottle in the freezer. The drying agent settles on bottom and the anhydrous acetone is readily available to pipette from the bottle.

Yes it's a good idea to do the evap test. I will skim through the threads.

 

[downwardsfromzero]

The key is to 'dose' the naphtha with IPA prior to adding the FASI. HEATING IS NOT NECESSARY

This also works for FASA pre-dosing the naphtha with acetone. I posted about this some time (years) ago, maybe not in much detail though.

 

[Nitegazer]

This also works for FASA pre-dosing the naphtha with acetone. I posted about this some time (years) ago, maybe not in much detail though.

Yep- you schooled me on this back in 2015. At the time I thought temperature was the key factor, though.