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Hi guys, I was thining about extracting some caffeine, just for fun.
Doing a simply A\B tek (don't know if by cooking or just sodium carbonating in a wet situation, I'll see), but I've only found around that DCM is good to extract.
Since it is too expensive for a game experiment, and the XlogP3 of Caffeine is -0.1, do you think also IPA, or Limonene, would do the work?

I don't even ask about naphta, Trichloroethylene and such, don't think they'd work.

Thanks,

Ari


edit: I just figured out an acetone wash + citric acid would give mi caffeine citrate, so no needing to pull out in freebase by DCM. Although I don't know if I'd pull some bad tannins or whatever... maybe using tea leaves is better than coffee. What do you think?
Thanks to everyone who will reply =)
Caffeine extraction is the sort of thing that most people do in Organic Chem lab in their first year. About half the O-Chem Lab books I have read/possessed over the last 20+ years has had an example of such in it. I don't have most of those books anymore but I think it's pretty easy like: Boil caffeine containing plant matter in water, let cool. Add sodium bicarbonate and extract with DCM. Separate and dry with drying agent before DCM is evaporated leaving caffeine. Don't quote me on that but a google search using the terms "caffeine" and "extraction" will yield you many results saying something similar I imagine.
If you read, I was asking how to avoid DCM, since it cost so much and is difficoult to find (as also other working solvents).

I think my salt approach should work... we'll see.
I would do hot water, then acetone on that...

You won't get any tannins or anything icky - those are mostly non-polar.

Acetone would work by itself too though.

Tea leaves, coffee leaves... doesn't matter. Coffee you would have to grind.
Citation :If you read, I was asking how to avoid DCM, since it cost so much and is difficoult to find (as also other working solvents).

Okay, google "dielectric constant" and chose ANY solvent with a dielectric constant lower than 15. A reasonable chart for this was found after 15 seconds of searching.

http://www.usm.maine.edu/~newton/Chy251 ... vents.html

Good luck.

Moriarty

P.S. I don't think caffeine will form salts with citric acid. Just a quick read tells me what I originally thought to be true on the matter. Unless, that is, I read it wrong in haste.

http://books.google.com/books?id=B9MAAA ... ne&f=false
I'm pretty sure acetone will work. Google 'solvent wiki' and scroll down to the table. You can usually swap solvents that are in the same group. DCM is a polar aprotic solvent, as is acetone.

I might give this a go myself, for t3h funz.

Luckily for me, I have about 15l of acetone and 5 of DCM - I was using them for cleaning some old paintwork / varnish up. Tounge
??? I did a search and found mixed information. Some pages claimed that DCM was non-polar and others that it was polar/aprotic as Peach claims. The bulk of the pages that claim it to be polar were respectable pages so I tend to believe it but polarity is generally a function of the dielectric constant. If a solvent has a dielectric constant lower than 15 it is generally considered non-polar. DCM has a dielectric constant of ~9. So how is it that it is polar?

I also found mixed answers for the polarity of carbon tetrachloride and chloroform although most pages clearly stated that both were non-polar? Intermediate polar solvents? Do they fit that classification?
Chlorine, remember is a very large molecule, and its outer most electrons can be very easily moved to-and-fro, which is why it creates Cl- ions when dissolved in a polar, from NaCl.

DCM has the ability to have a greater than 9 dipole moment when in contact with other polar molecules... However, I don't see it being able to create >15d from induced dipole-dipole interactions. So you do have a point...

I think DCM has a very important property of induced dipole/dipole interactions that may be underestimated... As the Cl atoms become either repelled/attracted to another polar molecule, the Hydrogen atoms will also become repelled/attracted to the carbon atom respectively, increasing the dipole moment greatly...... but there may be another factor I am missing?
I think DCM is on the cross over point between the two, it's constant is still twice that of the more polarized none polars, four times more than things like cyclohexane / toluene

Here's the trend for chlorination, just out of interest...

Methyl chloride = 12.9
DCM = 9.1
Chloroform = 4.81
Carbon tetrachloride = 2.2
Citation :Chlorine, remember is a very large molecule, and its outer most electrons can be very easily moved to-and-fro, which is why it creates Cl- ions when dissolved in a polar, from NaCl.

Given, DCM has some dipole movement but the electrnegativity of carbon is ~2.55 (I think) and chlorine ~3.1...Um, I think Wink. Not lots of dipole movement there but I am, of course, not an expert.

Citation :I think DCM is on the cross over point between the two, it's constant is still twice that of the more polarized none polars, four times more than things like cyclohexane / toluene

Here's the trend for chlorination, just out of interest...

Methyl chloride = 12.9
DCM = 9.1
Chloroform = 4.81
Carbon tetrachloride = 2.2

I like your answer. It is something akin to what I was thinking.

Acetone, I think is a loser without some serious modification. One, it's miscible with water. There are, of course, some things you can do to avoid this pitfall but DCM just seems easier, as does hexane, toluene, ect.

Citation :Acetone would work by itself too though.

I am not sure acetone will work well for caffeine extraction. Alone (probably no base required) it should extract caffeine but not with any level of selectivity. Again, I don't know but I think what I've suggested is sound.

Moriarty

P.S. Methanol and xylene are miscible but separate with any amount of water and a base like NaOH. I imagine it will separate with most water soluble solutions??? NaHCO3??? Either way I can't see how that might be applicable here.
I just finished extracting caffeine with both DCM and acetone

The results are -----> HERE
Hey i would advise using Tea leaves for your extraction as they contain more Caffeine than Coffee.

I did it with a Soxhlet which was the bomb ^^ Really neat white cristals at the end Smile
If its the caffeine you want i would suggest No Doze, pharmaceutical grade caffeine... but why do you want it are you going to add an imine and react. wow isnt that like tri-methyl something?