Sciencemadness Discussion Board

Skatole?

spong - 11-9-2010 at 22:44

I read that skatole could be made by reacting KOH and egg whites, probably from the tryptophan in the egg. Obviously it wouldn't be a good method for producing large amounts of it but I thought it would be interesting.
The KOH pellets were added to a film canister and egg white poured onto them, no reaction occured immediately so I capped and shook it and then left it to settle to the bottom. It formed a gelatinous lump at the bottom and warmed slightly (chemical omelet :D) but had no poo smell, just the slight eggish scent and KOH fumes.
I then heated it in boiling water and stirred the lump, forming a yellow foamy liquid but still no smell.
What's the story? Was that just a bad source of info or is there something wrong with how I did it?

zed - 12-9-2010 at 02:50

Why not make some? The synthesis of Indoles is remarkably easy, if you have any kind of access to reagents. The whole experiment should take an hour or so.

A little propanal, some phenyl hydrazine, some ZnCl2.....And, bingo!

You will be able to decide for yourself, whether pure Skatole smells like Orange Blossoms, or a stinky colon dump.




spong - 14-9-2010 at 00:30

I don't have any easy way of getting propanal I could maybe find some propylene glycol and make it from that though, MEK could be substituted for 2,3 dimethylindole which would probably smell similar... I think I would be banned from chemistry if I were to make a reasonable amount though :P

madscientist - 16-9-2010 at 11:41

Decarboxylation of indole-3-acetic acid? It's available as plant rooting hormone, but I don't think it'd be a cheap way to make your area smell like a stinky Godzilla dump.

hissingnoise - 16-9-2010 at 11:58

You do know that in trace amounts skatole smells sweet - but large quantities have a terrible spong. . .


spong - 16-9-2010 at 16:28

Quote: Originally posted by hissingnoise  
You do know that in trace amounts skatole smells sweet - but large quantities have a terrible spong. . .


Hehehehe :D
I've got some indole-3-butyric acid for my garden but it's a very dilute and expensive, plus that would give ethyl indole anyway. I would only be making a tiny amount, then the whole mix would probably be flushed down the toilet, where skatole belongs :P

zed - 16-9-2010 at 20:01

I've synthesized a number of related indoles. Unless you have actually smelled 'em, don't assume the literature is completely correct about their odors.

Much of the strong unpleasant odor of some feces, is clearly due to other chemicals. The vapor pressure of Skatole at body temperature is not very high.

Here we run into problems. What component, of the odor of feces, is actually supplied by Skatole? Gases, certain amines, and free fatty acids, all pack a pungent punch of their own.




madscientist - 17-9-2010 at 07:14

Occurred to me last night: if indole is readily available for you, I'm pretty sure you could add a methyl to the 3-position (namely, create skatole) by refluxing with methanol and a bit of sulfuric acid.

It works on toluene - a long time ago I created 1,3,5-trimethylbenzene, a red oil, by doing so.

You could perform the Fischer indole synthesis with acetaldehyde/phenylhydrazine to get indole if you can't find it for whatever reason. Both are easily within reach.

Granted it wouldn't be the cleanest reaction, but I'm guessing a little bit of skatole goes a long way. :P Worth looking into I think - if I find any references that offer credence to this theory I'll post them.

spong - 18-9-2010 at 04:49

Quote: Originally posted by zed  


What component, of the odor of feces, is actually supplied by Skatole? Gases, certain amines, and free fatty acids, all pack a pungent punch of their own.

I intend to find this out :D

Quote: Originally posted by madscientist  
Occurred to me last night: if indole is readily available for you, I'm pretty sure you could add a methyl to the 3-position (namely, create skatole) by refluxing with methanol and a bit of sulfuric acid.

It works on toluene - a long time ago I created 1,3,5-trimethylbenzene, a red oil, by doing so.

...that works!? I wanted to make mesitylene from toluene via friedel-crafts alkylation. Do you have any references for that? If it works with indole then making acetaldehyde would be much better than propionaldehyde, I don't have propylene glycol.

zed - 19-9-2010 at 02:18

The Fischer Indole Synthesis does not normally form Indole, from the phenylhydrazone of acetaldehyde. Doesn't work. Nope!

Reputed to produce Indole, if you run the phenylhydrazone through a tube furnace. But, the by-products of such a reaction might be none too wholesome.

Indole HAS been easily produced via the Fischer Synthesis, by the reaction of phenylhydrazine and pyruvic acid, with a ZnCl2/PCl5 catalyst, under microwave radiation. Sounds hard, but you just mix all of the components together, and nuke 'em in a conventional home microwave.

Since PCl5 is hard to come by.....Homemade, Microwave Synthesized PolyPhosphoric Acid, should be a suitable substitute.

Still, it ain't the way to go. Not if you want Skatole.

Just make yourself some propanal. Oxidize propanol, and distill off propanal as it forms.

http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2...

Once you have propanal, it's easy. Form the phenylhydrazone, and The Fischer synthesis will then produce Skatole directly.

Here in the States, Propylene Glycol is an easy "Get". About 10 Bucks a gallon. Ethylene Glycol is normal automotive antifreeze. Environmentally friendly "Green" antifreeze? Propylene Glycol!

[Edited on 19-9-2010 by zed]

[Edited on 19-9-2010 by zed]

[Edited on 19-9-2010 by zed]

[Edited on 19-9-2010 by zed]

Globey - 19-9-2010 at 07:33

Spong,

We all know you got that reference from Merck Index. When they are speaking of albumin, they are not talking of egg whites. Rather, it is usually the freeze dried or carefully dessicated (so as not to denature the protein). As you know, some proteins can tie up a LOT of H2O in their matrices. Also, you should know albumin could refer to plasma protein in a number of living things. Here they probably are talking about the powdered, finely milled, dessicated egg white powder. Your best bet is to go to some of the steroid brain places. They sell pure whey, pure albumin, and other top of the foodchain types of protein. My suggestion: have dedicated disposable heating retort (like iron pipe with one cap on bottom) to perform such reactions. They could really mess up any remaining glassware you may have. Hope the info helped! Now, there is one other route, but it ain't pretty: ever heard of the Atkins Diet or South Beach diet - basically high protein low carb diets. You can easily detect skatol in your regular skat, but you will greatly increase the yield by digesting more of these high protein foods. Especially milk, egg, etc. The extraction would make a stone man barf, but....there probably are better ways. Hope the insight helped!:cool:

spong - 19-9-2010 at 08:23

It was from the molecules with silly names website :P Argh albumen and albumin are so similarly spelled.
I read about extracting almumIn from fresh eggs with ammonium sulfate and acetic acid, we have chickens so I've got a lot of eggs to practice on :D