Sciencemadness Discussion Board

Synth Difficulty- Proprionic anhydride.

bmays - 11-5-2015 at 22:33

I have been having an annoyingly difficult time preparing proprionic anhydride. First try was a dry distillation from calcium propionic and sodium pyrosulfate, this resulted in a small amount of proprionic acid distilling over. Next try was acetone vapor through 20 feet of copper tubing heated red hot on a big propane burner, ketene was being produced and bubbled into proprionic acid, but i think acetone vapors were making it through and somehow turning the anhydride back to the acid. I don't know what is going on here honestly, huge amounts of ketene were being produced (smokey and horrendously choking gas). Still i could not obtain any anhydride when the results were distilled, seemed to be entirely proprionic acid boiling at 141c and no anhydride at 161c. Next i tried cyanuric chloride and proprionic acid in an attempt to distill out propionyl chloride, nothing comes over in a hot water bath, which it should because the boiling point is 57c... so i added some toluene and refluxed for a few hours. Now i think some proprionyl chloride distilled over with the toluene as an azeotrope, but still nothing boils out at 100c so its little use.

Ideas? Anyone done this? I don't have thionyl chloride or any of the phosphorous halides. I don't want to use bromine/sulfur. Maybe i need to make oxalyl chloride from my cyuranic chloride with oxalic acid. Then maybe i can get propyl chloride from my proprionic acid.

[Edited on 12-5-2015 by bmays]

Molecular Manipulations - 12-5-2015 at 00:04

Trying to make Fentanyl I bet, based on other posts, however maybe your dog is sick and you need a very, very strong pain killer (100 times morphine:o)?
Either way I don't care.
Ethenone is likely the way to go. Just because there's a strong smell doesn't mean you made much or had good yields. It has an extremely potent smell, and is about as toxic as phosgene or hydrogen cyanide - if you're still breathing you didn't inhale much. It's very reactive, can't see how it could react with copper though. Did you dry the acetone prior to use? How about the air?
I can't imagine why you didn't condense the unreacted acetone...
Was your propionic acid anhydrous? (Easy to separate from water using salt, so you've got no excuse).
How do you propose acetone could react with prop. anh.?


[Edited on 12-5-2015 by Molecular Manipulations]

byko3y - 12-5-2015 at 04:22

It's so, so bad. I realize that 15 years ago any schoolboy could make it at least half way to fentanyl. Thanks god nowadays those guys can't even make the first step, because it requires some knowledge they obviously don't have.
I'm pretty sure OP thinks that his isocyanuric chloride is a cyanuric chloride.
Because it's a begginnings section, I would give you a hint: try only well known tested procedures, and make sure you have at least superficial understanding of what's going there, because otherwise you might have made some cyanogen derrivative or other highly toxic stuff without an odor.
Btw, if you actually made the fentanyl, you would most likely die.

[Edited on 12-5-2015 by byko3y]

bmays - 12-5-2015 at 12:31

Fentanyl is outside of my grasps imo, looks hard as lsd. For drugs mdxx is the next step for me anyways, although i doubt i will even try that as im getting too old and it takes too long to recover after rolling. although i have been reading about demethylation of vannilin but we are getting onto a whole nother topic. I have made testosterone from dhea, now i want to add the ester, mostly because i can and it interests me. The esters arn't stable for long term storage, but again why would you care. Cyuranic chloride was purchased... i never did any tests beyond assuming i got what i paid for. Proprionic acid is anhydrous, dried with 4a sieves, and the ketene would have dried it anyways a small amount of GAA/AA wouldn't hurt. I was condensing the acetone, but the air cooled condenser was overheated and as soon as acetone started to come over the smoke like gas disappeared. I thought i might be wrong about ketene and acetone being nonreactive. I was outside in the wind, i only caught a small wiff and it gave me a minor headache. I can only assume the reaction between ketene and proprionic acid is so slow that bubbling it through is not effective because i cracked 100ml of acetone and bubbled it into into 15ml of acid. I ended up with 10ml of acetone and 15ml of acid, no high boiling fraction. idk. I know i never went to school for this and i'm dumb, thought i could pull it off though. I wanted a way to make gaa from vinegar as well, but i see now sodium acetate easier. I wanted aa as well, i think i was going to try a selective herbicide synth or something but i forget now, god damn violets in my lawn, in my country all these herbicides are banned.

[Edited on 12-5-2015 by bmays]