Triflic Acid
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Capsasin Hydrolysis
I'm trying to make vanillin from capsasin, so the first step is to hydrolyze the amide bond in capsasin. I've got some ethanol chili oil boiling in
hydrochloric acid right now, but even after a few hours no fatty acid oil has been produced. Is there something I'm doing wrong, or should I just
leave it boiling for longer?
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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DraconicAcid
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Amides are a pain in the expletive to hydrolyze. The only time I've successfully hydrolyzed piperine was with KOH/H20/ethylene glycol in a nickel
crucible at 130 C for several hours.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Garry63566
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Maybe try to use a base for hydrolysis of amides like KOH/EtOH and reflux(?)
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Triflic Acid
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I didn't want to have to use a base, because then everything stays in solution, including the acid salt and the amide. That makes the whole thing a
pain to work up. So, I guess I should just keep boiling. Is there any catalyst that could be used?
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Garry63566
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Probably leaving it for longer would be an option, as primary amides need like 2.5 hours reflux in HCl and secondary amides might need much longer
time to react. Also, is ethanol refluxing or is there only a small amount of ethanol that doesn't impact reaction temperature much, as I think primary
amides need HCl reflux so if only ethanol is refluxing the temp might not be high enough idk
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Triflic Acid
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Its at 104 according to my thermocouple, since its only ~20mL EtOH and 100mL HCl
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Triflic Acid
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Update: I ran the acid reflux for another few hours today, and still no visible amount of oil. I think that the ethanol chili oil didn't have much
capsasin. So, I'm biting the bullet and buying some pure capsasin powder from ebay. Before I waste that too, since its pretty expensive, does anyone
have a procedure that they know works for these kinds to reactions? Preferably using acid instead of base since that makes the workup a lot easier,
but if only base will work I'm willing to use that too.
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Triflic Acid
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Okay, so as of right now I think I have a similar prep to follow: http://www.sciencemadness.org/talk/viewthread.php?tid=79854 Any big changes I should make to that?
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Boffis
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Hi Triflic acid, sorry about my U2U question I hadn't seen this thread then. I think alkali hydrolysis will probably work on this substrate but I can
see a few potential problems. The sodium 8-methyl-6-nonenoate salt will probably act as an emulsifying agent with little tendency to crystallise.
Partial neutralisation of the alkali with CO2 or NaHCO3 may be enough to precipitate the vanillylamine. If you are lucky and the amine is very
insoluble in the resulting strong sodium carbonate solution you may be able to just filter it off but Sod's laws states that this will not happen  . Extraction with ether or some other weakly polar solvent might work but I think an
intractible emulsion is a more likely outcome. Strongly acidifying the mixture and then trying to steam distill out the nonenoic acid might work, if
the acid is volatile enough, and then neutralise with sodium carbonate to pH 7-8 so as not to de-protonate the OH group should then allow the amine to
be extracted by filteration or a solvent.
Be careful though, high-test capsaicin extracts are so rapidly debilatating that they are as hazardous as oleum or bromine even if the effects are
less severe in the longer term!
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Triflic Acid
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Maybe high temp vaccum distiliation might work? Where did you get your initial piperine from? Do they sell capsasin extract? Also, would a fume hood +
dust mask be enough to weigh it out safely?
[Edit: The amine is pretty soluble  19g/L. Looks like distilling is the only
option.]
[Edit2: Just checked, turns out the amine is actually pretty stable to heating, and will boil at 290]
[Edit3: Actually, no one lists a bp. Thinking that it sublimes at 290.]
[Edited on 30-4-2021 by Triflic Acid]
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Boffis
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Hi Triflic, Since capsaicin dust irritates the eyes like hell you need to protect the whole face. A fume hood with a good draft should be OK. Remember
to wash your hands and forearms thoroughly with soap and COLD water before you accidently touch your face or bum!! Hot water causes the capsaicin to
migrate into the oils in your skin and then its harder to remove.
The solubility of capsaicin is in water, the presence of high concentrations of salt should reduce that considerably and also increase its tendency to
partition into say ether or MIBK. So I think I would try an alkaline hydrolysis followed by acidification with 36% HCl, steam distill to remove the
alcohol and the 8-methyl-nonenoic acid and then neutralise by exposing to CO2 gas to see if you can precipitate it directly or extract with a solvent
like ether or MIBK (methyl-isobutyl ketone). Ether is preferrable as it is easier to remove. The amine may be soluble in DCM but I am not sure, if so
this could be used for the extraction.
I think that if you try to recover the amine with first separating the fatty acid you will end up with a mess as I mentioned above.
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Triflic Acid
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On second note, I realized that there is a better way to deal with the capsasin. I think that I'm going to buy a 5gram bag of it and dissolve the
whole thing in ethanol, no weighing required. Also, found a patent that claims that they used dcm to extract the amine, so I'll do that. So as of now,
here is my plan:
1) Do a base hydrolysis in ethanol
2) Acidify to get rid of the organic acid
3) Do a DCM washing to get out the amine
4) Maybe sublime it if I have to.
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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Triflic Acid
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Bad news, turns out that no one will sell capsaicin other than some eBay sellers that don’t look trustworthy.
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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zed
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Well Vanillin from Capsaicin, is just Vanillin. Though some manufacturers charge a vey high premium for it, claiming it is "Natural Vanillin" or
Vanilla. Cayenne is perhaps 1% Capsaicin. Which would be about 10grams/Kilo. Cayenne costs about ten bucks a kilo in the U.S..
There are a few papers out there, that utilize enzymatic hydrolysis to obtain the Amine.
I'd try really hard to find a good procedure some where in the literature.
Vanillylamine looks like it might be amphoteric. Fickle.
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Triflic Acid
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I really don't want to have to do an enzyme hydrolysis, I don't know a thing about Biology. Also, I would rather not have to extract from Cayenne,
since there are a bunch of other things in there that might contaminate the product.
There wasn't a fire, we just had an uncontrolled rapid oxidation event at the power plant.
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