Author Topic: Catechol from Salicylamide?  (Read 101 times)

no1uno

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Catechol from Salicylamide?
« on: November 22, 2009, 10:01:41 PM »
Just had a thought, salicylic acid is cheap, you don't have to deal with over-inquisitive photography shops (the one here is SUPER inquisitive) and simple as shit to acquire in bulk (homebrand aspirin for starters)...

Formation of the amide would be a simple matter of hydrolysis of the acetylsalicylic acid, then collecting the ammonium salicylate product (ie. use ammonia instead of NaOH) & heat the piss out of it to get the amide (note the mother liquor from the removal of the ammonium salicylate will contain ammonium acetate and really should be kept)

A Hoffman (bleach) on that would give 2-hydroxy-aniline, hydrolysis of which (phosphoric acid is known to work on similar substrates) would give catechol.
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Sedit

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Re: Catechol from Salicylamide?
« Reply #1 on: November 22, 2009, 10:40:23 PM »
Nice No1and I have been thinking of the same thing recently although your way is the long way around. There are methods detailed in the Phenol thread I believe it was over at Science Madness that you may want to look into. They make mention of a way to decarboxylate benzoic acid to phenol using a copper catalyst. Ill take a look in a little bit and see if I can find the reference.
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Vesp

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Re: Catechol from Salicylamide?
« Reply #2 on: November 23, 2009, 05:01:30 AM »
I like this method, seems nice and easy.

Sedit, are you sure they weren't talking about benzoic acid into benzene, and salicylic acid into phenol? either way, you've got to add an OH later on.
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Sedit

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Re: Catechol from Salicylamide?
« Reply #3 on: November 23, 2009, 05:18:53 AM »
Possitive they where discussing the direct reduction of benzylic acid to the phenol using a copper catalyst. Damn im going to have to look for it now so I can put up or shut up.
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Sedit

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Re: Catechol from Salicylamide?
« Reply #4 on: November 24, 2009, 01:00:10 AM »
Told ya Sedits got your back No1uno, Im just shocked I remebered that I seen it  ;D..... And where I seen it :o

Quote from GC over at SciMad.
Quote
There is also an industrial method for phenol production that employs oxidative decarboxylation of benzoic acid with copper salts as catalyst. This directly gives phenol instead of benzene.
These are the patents for the process:

Dow Chemical, US 2 727 926, 1954 (W. W. Kaeding, R. O. Lindblom, R. G. Temple).
Dow Chemical, US 2 954 407, 1957 (W. H. Taplin).
Dow Chemical, US 3 235 588, 1962 (C. W. Weaver).

http://www.sciencemadness.org/talk/viewthread.php?tid=3298#pid165857
Enjoy searching for them. What works there has a good chance of doing the same for Salicylic acid to Catechol.

Heres a couple for you,
United States Patent US3379774

Phenol from Benzoic acid using CuO and MgO
http://www.freepatentsonline.com/3379774.pdf

Conversion of Benzoic acid to phenol using Nickle and iron oxides
US Patent 5268512

Catalyst and process for producing phenol
http://www.patentstorm.us/patents/pdfs/patent_id/5268512.html

Chances are the temperature must be kept high to distill the catechol as it forms or else this condensation reaction can possibly form
http://www.anl.gov/PCS/acsfuel/preprint%20archive/Files/48_2_New%20York_10-03_0615.pdf

Of course all this is one thing, but there is also the possibility of decarboxylating the Salicylic acid to yeild phenol and then treat this with Fentons reagent which would yeild a variety of neat things such as Hydroquinones, Resorcinol, and Catechol.

« Last Edit: November 24, 2009, 01:29:40 AM by Sedit »
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no1uno

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Re: Catechol from Salicylamide?
« Reply #5 on: November 24, 2009, 05:52:09 AM »
Thanks to SM I am able to search the appropriate literature more easily, in Organic Reactions, Vol 3. starting from page 267 there is an extensive overview of the Hofmann Rearrangement.

At page 291 thereof, there is a table which shows that the initial product of the Hofmann rearrangement of Salicylamide with Hypochlorite (NB not Hypobromite, which gives ring brominated products ONLY) is the 4,5-benzoxazole, which on hydrolysis gives 2-hydroxyaniline. I'm just chasing down the reference information from the Organic Reactions article (their reference number is #48) to see if I can grab the reference details then I'll request the article/citation.

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SOMA

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Re: Catechol from Salicylamide?
« Reply #6 on: November 26, 2009, 07:59:31 PM »
As pointed in an ignored sciencemadness post, what would one obtain if he reacted phenol instead of vanillin as per the following patent?

http://www.freepatentsonline.com/4465864.html

heisenberg

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Re: Catechol from Salicylamide?
« Reply #7 on: December 06, 2009, 02:16:31 AM »
As pointed in an ignored sciencemadness post, what would one obtain if he reacted phenol instead of vanillin as per the following patent?

http://www.freepatentsonline.com/4465864.html

You'd probably get p and o iodophenol.
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