Sciencemadness Discussion Board

extraction an re-X without distillation suficcent?

postart - 22-12-2010 at 15:13

hello all,
I am curently researching the ritter reaction (acetonitrile variation). Anyway I have a rb flask, reflux condencer, magstir/HP, beakers, but "no distillation apparatis"; and wanted to get a second opinion on pollar/np washes, followed by a/b extraction, and finnaly a slow recrystalization to obtain a suficcently pure product.
Also would a 28% solution work to reduce volumes in the hydrolysis?

Thanx!

ScienceSquirrel - 22-12-2010 at 15:37

Meaningless question really unless you specify the reactants and the product.
Supposing I was making some ethers; dimethyl ether would be a totally different kettle of fish to isolate and store compared with methyl benzyl ether.
Even closely related inorganic compounds need very different procedures; sodium chlorate has an unhelpful solubility curve in water and is hard to crystallise, potassium chlorate has a very helpful solubility curve and crystallises like a dream.

postart - 22-12-2010 at 15:45

md-allybenzene, acetonitrile, H2SO4; hydrolysis by 15% HCl. product 3,4metheleendioxyamphetamine.

[Edited on 22-12-2010 by postart]

ScienceSquirrel - 22-12-2010 at 15:53

Kind of thing you have to do a literature search on really.
It is the sort of thing that you will want to get exactly right with no contaminants or side products, for your own satisfaction as a chemist of course :D

Sedit - 22-12-2010 at 16:37

Isn't the ritter reaction for the synthesis of Methylene Dioxymethamphetamine prone to ring closure forming a completely different substance then one is after in a normal ritter reaction.

I suggest you read read and read some more. Some DEA microgram letters on the impuritys found via this method may be a good place to start.

Nicodem - 23-12-2010 at 07:41

Quote: Originally posted by Sedit  
Isn't the ritter reaction for the synthesis of Methylene Dioxymethamphetamine prone to ring closure forming a completely different substance then one is after in a normal ritter reaction.

That is exactly why I keep on insisting in the use of references. If the original poster would have ever bothered to do a literature search in order to provide a reference for his claims, he would've avoided posting nonsense like this:
Quote:
md-allybenzene, acetonitrile, H2SO4; hydrolysis by 15% HCl. product 3,4metheleendioxyamphetamine.

Also, if he would have posted in the proper forum section then he would at least got an explanation on why that is nonsense and perhaps someone would have bothered pointing him to the proper reference. Instead, I have to waste time with it and move the thread to its place.

xwinorb - 23-12-2010 at 15:50

I have tried the Ritter reaction for this particular synthesis, it does not work. If you look into some classic reference books like TSII or SOMM, you will see in the later editions very clearly stated "DO NOT TRY THIS METHOD".

When I tried it, it got a bit exhotermic and then everything became a bunch of black tar. This was more than 10 years ago.

I would advise you and others also, take care with sassafras oil imitations. Now a days most of what you can find is not good sassafras oil. Do a boiling point test, if it is not within the boiling point of safrole ( 232 C ) plus minus 2 deg C don't use. Most of the fake stuff does not smell like sassafras oil either.

Also, if you don't distill don't expect good results.

I am posting this one just to save you and others a lot of time and reagents waste.



quick question on the ritter reaction

postart - 26-12-2010 at 22:39

I heard that the use of strong acids in the ritter reaction will destroy the methylenedioxy bridge on safrole. Have any yeilds ever been documented? Would the safrole be reduced to allybenzene resulting in amphetamine?

Ephoton - 26-12-2010 at 23:09

hmmm wrong forum buddy.

safrole allybenzene resulting in amphetamine.

NEWBEE thread and rhodium for you.

and yes strong acids cleave the methylenedioxy ring.

though not completely which is a true pitty.



[Edited on 27-12-2010 by Ephoton]

turd - 27-12-2010 at 08:56

Quote: Originally posted by postart  
I heard that the use of strong acids in the ritter reaction will destroy the methylenedioxy bridge on safrole. Have any yeilds ever been documented? Would the safrole be reduced to allybenzene resulting in amphetamine?

One problem with ring-substituted allyl-/propenyl-benzenes and derivatives is that they tend to oligomerize (i.e. form the dreaded red/black TAR). That's why many procedures which work fine for plain amphetamines fail for alkoxy substituted amphetamines. I don't know if this is the case here though.

Anyway, there is no way you would get rid of the two oxygen atoms on the ring and even if you managed to, it would be a freaking blasphemy! Shame on you for even thinking about that!

PS: This is a science board. Starting with "I heard that..." is considered very rude. Give your references and let them not be some shoddy newsgroup posting.

postart - 27-12-2010 at 13:15

Thank very much for the replies! Sorry about the "I heard" it was just a discussion amoungst friends. I was a little worried if this post would be taken as good or bad so again thanks!

turd - 28-12-2010 at 01:32

Quote: Originally posted by postart  
I was a little worried if this post would be taken as good or bad so again thanks!

Frankly, there are a few things in your post that could rub people the wrong way. First of all you chose the wrong subforum. You gave no reference except an ominous "I heard". But for me the worst: you were already told all that (https://www.sciencemadness.org/whisper/viewthread.php?tid=15...) and chose to ignore it and did not even mention it! Are you kidding us? IMHO the the slightest sense of decency would dictate that you start your thread with something like "Hey guys, I've had a thread on this: [link], but the answers are not satisfactory, so could you please explain [...]".

Nicodem - 28-12-2010 at 02:57

The crossposted threads were now merged.
Quote: Originally posted by postart  
I was a little worried if this post would be taken as good or bad so again thanks!

What an interesting oxymoronic declaration. It is like saying: "I was afraid of a house fire, so I set the house on fire by myself." How about starting to worry about the real issues here, like you showing a complete disrespect to other member's efforts, the forum culture and in particular to science. You were already given the direction on where to find the exact and detailed answers to your question, yet you are so handicapped by laziness that you find it less problematic to behave disrespectfully to the forum culture!