Yugen
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An Easy Resorcinol Dimethyl Ether Prep?
Background
While surfing Organic Syntheses I came across an interesting prep for 2,6-Dimethoxy-benzonitrile. Here's the link.
So I've never seen a reaction like this before, but I assume the it works because the nitrile is drawing electrons away from the nitro groups,
allowing those groups to leave and be replaced by deprotonated methanol. Because of this I am guessing that this makes this synth pretty limited
(probably to only ortho-subbed nitro groups)... However, since most phenol ether preps use carcinogenic alkylating agents (e.g. Methyl iodide or
Dimethyl sulfate), I figure people should still check this out.
The Question
So if I wanted to turn this into a synthesis for Resorcinol dimethyl ether, how would I go about it? I am guessing that I could hydrolyze the nitrile
to its benzoic acid and then heat it up to release the group as CO<sub>2</sub>? I figure that would work because it works for turning
gallic acid and salicylic acid into their respective phenols...
Hmmm, I have this funny feeling that there's a better way to go about this though. I have seen other examples for non-aromatics where nitriles are
just striped away with in one step (e.g. it's a step in glutarimide preps). Do you know how I could do this more directly? This would be a pretty
slick way to Resorcinol dimethyl ether if you do.
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Yugen
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An easier question
Wikipedia's article on nitriles says...
Quote: |
Nitrile groups in organic compounds can undergo various reactions when subject to certain reactants or conditions. A nitrile group can be hydrolyzed,
reduced, or ejected from a molecule as a cyanide ion. |
Does anyone know what they mean by "ejected"? How does that happen? What is the reaction mechanism for that?
[Edited on 6-1-2015 by Yugen]
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Yugen
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The magic words I was searching for were "reductive decyanation".
A bittersweet victory though... of course the reaction is catalyzed by a platinum group metal. O-chemistry man... always demanding we melt down the
world's treasure to get anything done...
Attachment: Rhodium-Catalyzed Reductive Decyanation of Nitriles.pdf (372kB) This file has been downloaded 967 times
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Scr0t
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Quote: |
O-chemistry man... always demanding we melt down the world's treasure to get anything done |
Therein lies the value i.e. usefulness combined with rarity. What else would you use it for? Jewelry!?
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CuReUS
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try using copper instead of platinum,I have seen many reactions in which copper can be used instead of costly metals
eg-in the arndt-eistert reaction,the diazoketone can be converted to acid using Cu instead of Ag
http://en.wikipedia.org/wiki/Arndt%E2%80%93Eistert_reaction
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Yugen
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Perhaps... maybe Cobalt too because it's in the same group as Rhodium... I suppose... that's just not a very satisfying place to end my research given
the other articles I have seen dangled right out of my reach.
This source for example, The Reductive Decyanation of Nitriles by Alkali Fusion sounds really nice... just wish it wasn't $48. Why can't all journals have readcube or
deepdyve renting services?
Knowing my luck the paper will say something like "does not work on aromatic substrates" and I will be out a bunch of money for nothing. The article's
cross reference page might be worth it alone though...
Quote: |
The reductive decyanation of nitriles, as depicted in Scheme 1, has been reported employing metal hydrides,<sup>5</sup> transition metal
complexes,<sup>6</sup> electrolysis<sup>7</sup> and alkali metals in a variety of solvents.<sup>8</sup>
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It's tempting, but I always seem to leave these investigations with a $150 less in my bank account (because I bought two or more articles after the
first one)... Anyone here have a Taylor & Francis journal subscription (and a heart of gold) to get this for me?
[Edited on 7-1-2015 by Yugen]
[Edited on 7-1-2015 by Yugen]
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CuReUS
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enjoy
http://www.tandfonline.com.sci-hub.org/doi/abs/10.1080/00397...
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Yugen
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Thank you!
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Chemosynthesis
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Depending on the semantics, another form of "ejection" may be something akin to the Bruylants reaction, even though this is really a substitution. Not
really relevant to your desired reaction, but still occurs.
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CuReUS
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the only reaction that I know which uses a cobalt catalyst is the oxo process,and rhodium was found to be even better than cobalt
http://en.wikipedia.org/wiki/Hydroformylation#Catalysts
but its worth a try,chemistry works in mysterious ways
this article is a good review of reductive decyanation.There is even photoinduced decyanation
http://www.arkat-usa.org/get-file/23059/
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