about PEA (phenylethylamine) in chocolate

hmm.....I am not going to do extraction any more. I want to make PEA, how?

well....this is a project, I and my group members are going to put PEA into perfumes.

thank you very much~
but........I am very confused,
how to purify?
what is an inert solvent?

yes.......

Quote:

Originally posted by smile Quote: Originally posted by vulture Let's see, you're going to carry out an organic synthesis, but you have no clue what an inert solvent is or how to purify your product? yes.......

"Using excess benzene would prevent polyalkylation, but that would open up the possibility of polyarylation of the ethane."

That's why I said purify .

I was half-joking anyway...

Quote:

Glad we got that cleared up. Wait--it get's worse. Not only do you have no understanding of the concepts needed to successfully complete such a synthesis, you seem to have no understanding of what your target is. The PEA in perfume is phenylethylalcohol, not the amine, found in chocolate, among other things. oh...I see... Very briefly, inert solvents are those that won't react with anything that you're using in the reaction, under the conditions you use. Water, for example, has many excellent properties as a solvent, but it is also somewhat reactive, i. e. not inert in many reactions. Purification is needed because the thing you have when you're done your reaction contains not only the product, but the solvent, unreacted starting materials, and products from side reactions. It can be done in many ways. Some of the basic techniques are recrystalization, distillation, and chromatography. oh, I got it. Well....I just learn the purifying method last week.. I have my doubts about the current proposed strategy. Using excess benzene would prevent polyalkylation, but that would open up the possibility of polyarylation of the ethane. One possible alternative is to start from styrene, react with aqueous peracid (you could try cold permanganate), dehydrate the diol with H<sub>2</sub>SO<sub>4</sub>, and do a reductive amination. All these reactions should be found in standard organic texts. can I use the method given by Nick F? I don't have any organic texts.. Rhodium's drug chemisty site gives plenty of procedures for compounds of this type. Decarboxylation of phenylalanine is attractive. can I know the address of the site?

Indeed it is.

As Esplosivo said, it will be extremely hard to purify it from chocolate, simply because it contains many additional semi-unpolar substances, such as fats, flavourings etc.

Unless of course, you have a fully equipped chromatographic laboratory.

For an initial (crude) purification of PEA from chocolate, I suggest the following:

1) Melt 500g of chocolate in a large amount of water, and stir for a long time. Hope that most of the sugar dissolves. YOu have to use a very large amount because the PEA conc. is so low.

2) As phenylethylamine dissolves in water (checked Roempp, it dissolves in H2O, EtOH, ether), it should be in the aqueous solution BELOW the molten fats (fats are lighter than water).

3) Add alcohol, and precipitate whatever is not soluble in alcohol. Discard precipitate, and keep the filtrate.

4) Now, evaporate the alcohol. Get rid of it. Then add H2SO4 (strongly dilute), to form the phenylethylamine salt, until a low pH is reached (i.e. pH 2). At this point, filter out any precipitate once again. Discard it.

5) Add Ether (which preciptiates ionic compounds), or possibly ehtanol. This should precipitate the ionic salt of PEA (I.e. PEA HSO4), among everything else that behaves similarly. This should contain a highly concentrated version of PEA HSO4 however.

6) Take the precipitate, and add CaOH2 (in aqueous solution). CaSO4 should form, and precipitate. Phenylethylamine should be in the solution above. A slight ammoniakal smell should be noticable (this is what it smells like).


Many people have been wondering about PEA in chocolate. Studies have shown however, that PEA is broken down in the stomach, and thus only very small amounts reach the brain. There are more susceptible individuals however.

I suggest you search google with 'phenylethylamine in chocolate', it turns up heaps of links.
For instance,
http://www.chocolate.org/pea.htm
http://panicdisorder.about.com/cs/shfitness/a/chocolate.htm
and so on.


Sadly I have a feeling that my effort here is in vain - so I suggest, smile, before you ask further questions (that is a warning), to just read up a little bit to find out more about chemistry, purifications and so on.
You cannot expect us to walk you through a full synthesis/purification without even knowing what inert solvents and so on are, and without any will to look up the address yourself for Rhodiums site, and ... indeed, without bothering to find an organic chemistry text book, which can be found in the smallest of libraries!!
Make some effort!

Ok, good to know.
Does emulsion mean though that water solutes don't go into solution, though? I should think they would (providing good heat, and rigorous stirring)
In case of an emulsion - I guess one could try centrifugation, fat globules are going to be lighter than water & solutes, and thus separate. (As most will lack a centrifuge, you could probably just wait until it settles - gravity is just a weak centrifuge )

[Edited on 13-4-2004 by chemoleo]

yay I get to help

Pea in chocolate beurk....I prefer peanuts à la snickers or M&M's...

No just kidding.

My idea is:
Cl-CH2-CH2-NO2 + AlCl3 + excess benzen --> C6H5-CH2-CH2-NO2 + HCl

Then
C6H5-CH2-CH2-NH2 via Zn/HCl or SnCl2/HCl or Fe/HCl

The other idea is:
C6H5-CH=O + CH3-NO2 -H(+)-> C6H5-CH=CH-NO2 + H2O
Hydrogen en catalyst goes to the desired compound.

Or:
C6H5-CH=CH2 + HCl --> C6H5-CH2-CH2Cl
C6H5-CH2-CH2Cl + exces NH4OH --> C6H5-CH2-CH2-NH2.HCl

Now if one wants to get it the hard way...OK.
First add HCl to molten chocolate (Vulture is right cacao powder is way easier to process than chocolate).Mix well for intimate mix.
The HCl will make a salt of all the amino groups.It may hydrolyse a little some faty esters but those will remain unsolubles...Except some weird aminolipids...Cool down and filtrate the greases and precipitates...The watery acidic layer will contain the compound as a salt but also suggars ...

Then neutralise with concentrated amonia in excess...PEA will be then become unsoluble in water and be extractible with ether aside with other aminated molecules..Suggars and acids,salts and alcools will remain in water.
Evaporate...you have an enriched Pea etheral solution...

This process only took 2 steps!

For further purification it can be handy to get...silice TLC( thin layer chromatography) and to make single and 2D elution...
PEA should be viewable under UV.
Usually it will stick to the TLC plate unless you use a tiny % of amonia in butanol...0-3% can allow migration from 0% to 100%.

The ideal way would be to synthetise a little to get the stuff as standart and make tests to get the best butanol/amonia sothat good elution and Rf numbers (migration related).