smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
Removal of an Aryl Amine
The substrate has an alkyl chain, a hydroxyl group, and an amine on a benzene ring.
I'm having a hard time finding literature beyond the diazonium salt reduction with H3PO2(DEA list 1, strictly controlled compound ). I was wondering if there was any other way because of course H3PO2 is unattainable
to the amateur chemist because of shit-head meth cooks. Granted the stuff sounds kind of spooky anyways... Could other reducing reagents work that
wouldn't reduce hydroxy groups as well?
The only other thing I can think of that sounds some-what feasible is sandmeyer to substitute with the halogen(Cl is most practical), then
hydrogenolysis? Although hydrogenation tends to saturate the aromatic ring(?), and is kind of extreme(and I've never performed one in a lab, let alone
at home).
Thanks for any ideas as always sci mad!
|
|
|
Picric-A
National Hazard
Posts: 796
Registered: 1-5-2008
Location: England
Member Is Offline
Mood: Fuming
|
|
Im not quite sure what your asking, do you want to completly get rid of the amine group or turn it to a hydroxyl group?
Ethanol can reduce diazonium salts to hydroxyl groups, in turn being oxidised to acetaldehyde. Ths procedure is rather low yielding but very simple
with cheap reagents.
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
Sorry for not being very explicit I wrote this post at like 5:00 a.m. or something.
I want to completely remove it. I'm using the amine group to ortho-direct, and then want to remove it in the next step.
edit - hehehe, yes actually you are right. Ethanol will do the same thing in the sandmeyer as H3PO2(cleave the amine). Your misunderstanding of my
question (thinking I wanted a hydroxyl when I want only a loose hydrogen) lead me to the answer. Serendipity  !
Can anyone scoop this up, wish I had access: Awesome simple easy to acquire green reagents!
http://www.sciencedirect.com/science/article/pii/S0040403901...
I'd throw this into the reference request thread but it is most relevant here imo.
Thank you!
[Edited on 8-8-2011 by smaerd]
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
I just love to quote myself:
Quote: Originally posted by Nicodem  | | Though hypophosphorous acid is commonly used for the reduction of diazonium salts to aromatics, many other compounds from where the hydrogen atom is
easily abstracted also work. There are methods developed using various alcohols (like already mentioned), formamide, DMF, THF and other reducents.
Just search the literature or read a book/review on diazonium salts. You should be able to find plenty of alternatives to hypophosphorous acid. Given
that ethanol often works relatively well, I see no problems in using it given its availability. |
Try also the joy of UTFSE!
|
|
|
smaerd
International Hazard
Posts: 1262
Registered: 23-1-2010
Member Is Offline
Mood: hmm...
|
|
Thanks again nicodem. Have to say I am very grateful that there are people as yourself and others around here. It is what makes this community an
invaluable resource for a beginner.
My apologies for not being able to find that post. Like I said I was having a hard-time finding literature(let alone concepts). Your post is helpful.
I will look harder next time before posting.
Feel free to delete this thread if you feel it's dead bandwidth.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
