Sciencemadness Discussion Board

An Easy Resorcinol Dimethyl Ether Prep?

Yugen - 6-1-2015 at 08:10

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.

An easier question

Yugen - 6-1-2015 at 11:58

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]

Yugen - 6-1-2015 at 12:41

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 968 times

Scr0t - 6-1-2015 at 16:22

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!?

CuReUS - 6-1-2015 at 23:36

Quote: Originally posted by Yugen  

A bittersweet victory though... of course the reaction is catalyzed by a platinum group metal.


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

Yugen - 7-1-2015 at 00:28

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>

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]

CuReUS - 7-1-2015 at 00:34

enjoy ;)

http://www.tandfonline.com.sci-hub.org/doi/abs/10.1080/00397...

Yugen - 7-1-2015 at 00:39

Quote: Originally posted by CuReUS  
enjoy ;)


Thank you! :D

Chemosynthesis - 8-1-2015 at 04:22

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.

CuReUS - 8-1-2015 at 08:47

Quote: Originally posted by Yugen  
maybe Cobalt too because it's in the same group as Rhodium


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 :o
http://www.arkat-usa.org/get-file/23059/