menchaca
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resorcinol from salicilic acid?
this is my idea.....
C6H4(OH)COOH+1/2 O2-->C6H4(OH)2 +CO2
could this work?
thanks!
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Marvin
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I dont know any way of doing what you are after directly. The only thing I can suggest, is to decarboxlyate to phenol, dist/powdered glass (Ca(OH)2
may or may not give reasonable yeilds), then convert to a mixture of C6H4(OH)2 compounds with peroxide/Fe(II) followed by seperation.
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Polverone
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hmmm
Fenton's reagent (the oxidation system of Fe2+/H2O2) is very powerfully oxidizing. I've never seen it used in synthesis, though I've
attempted to use it myself for such purposes with little success. It can oxidize almost any organic compound into water and CO2.
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Marvin
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It is very powerful, its a free radical mechanism, but Ive read in several books, its one method of introducing OH- onto a benzene ring. They will
be mixed isomers, and probably more than a little of unreacted phenol and trisubstuted phenols as well given a strickly stociometric amount of
peroxide.
I admit, I havnt used it myself. The only alternative that springs to mind, is the mindless and rather long winded, nitration of benzene to dinitro
benzene, reduce with iron and acid, diazotise, boil. For something as industrially trivial as resorcinol, this is rather a lot of effort.
Maybe if we were told the use, we could suggest alternatives.
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menchaca
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well.. i want it to make lead stifnate
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Marvin
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I suspect the simplest method here from what you have would be to make picric acid, and oxidise that, maybe with fentons, maybe by chloriniting it/dil
NaOH, maybe by furthur nitration and then using the very reactive meta nitro group.
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menchaca
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that could be make react the picric acid with HCl and later with NaOH?
what conditions are nedeed?
the OH will be situated in the correct place i mean the meta orientation(does it write so?)?
thanks!!
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BASF
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Another proposal:
1.) protecting the OH-group of phenol by making an ether
1a).a voluminous tertiary alcohol, at least tert-butyl-alcohol is reacted in 15% NaHSO4-solution or similar at 70°C with the phenol
b)-the second effect is that we block the two ortho-positions and simultaneaously make the substituent meta-directing
2.)adding the second OH by either
- chlorination followed by cooking violently in NaOH (danger of cracking the molecule)
- nitration-reduction-diazotisation-hydrolysis;
- or amination(NaNH2, liquid NH3)-diazotisation-hydrolysis
3. last step is hydrolysation of the ether in acidified media, 25°C, to yield (hopefully) the desired 1,3-dihydroxybenzene(resorcinol) in acceptable
yield and -i suppose- relatively high purity.
  
HLR
[Edited on 8-4-2003 by BASF]
[Edited on 8-4-2003 by BASF]
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menchaca
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thanks a lot !!
i think is easier to me the way of the picric acid, can you tell me more about this?
i hope not to be tiring(does it write so?)
thanks again!!!
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Marvin
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Something bothered me about this, I think I know what it is now.
Why would a large alkyl ether be meta directing?
Alkyl groups are electron donating, so we would expect a large alkyl ether to be more strongly electron donating than a methyl ether, the ring to be
more reactive, and the substituent to be more strongly ortho para directed, no?
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