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Author: Subject: 4-Ethoxyphenol / hydroquinone monoethyl ether
Barium
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[*] posted on 18-5-2010 at 05:33


Before I got my equipment for pressurized hydrogenations I had terrible problems reducing all kinds of oximes, untill I stumbled upon Al/Ni-alloy in this article:
Reductions with Raney alloy in alkaline solution. B. Staskun, J. Chem. Soc. (C), 1966, 531-532.
For hydrogenations I'd use Rh/C (or Rh on acidic alumina) instead of Pd/C. If Raney Nickel is chosen you would have to use a really active version or a freshly prepared one in order to avoid having to use high pressures.
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turd
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[*] posted on 18-5-2010 at 22:03


Thanks Barium, but I think Nicodem's objections are justified. What I probably got _is_ the oxime. Shulgin describes all amines as oils and this was very eager to crystallize. I will try to organize an NMR to get a definite answer, but a small scale chemical test should also discriminate between oxime and amine.

Sorry for the noise. :o
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Barium
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[*] posted on 19-5-2010 at 07:13


I can't recall ever seeing a nitroalkane being reduced to a oxime. It can be a hydroxylamine though as those are very prone to crystallize and are known intermediates in the reduction of nitroalkanes. A simple test for hydroxylamines is to react it with Tollen's reagent. A positive reaction forms a silver mirror in a clean test tube.
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turd
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[*] posted on 24-5-2010 at 02:34


Sorry for the delay. To make a long story short (don't drink while doing chemistry, I'll spare you the details): the product was quite basic, isolated as the acetate and - there is no doubt about it - is the amine. The whole matter is still very curious. Why is it a very rapidly crystallizing solid (matters of seconds) when Shulgin describes all related amines as oils? How comes it didn't need significantly higher temperatures to distill than the corresponding amine without beta-methoxy functionality?
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Methansaeuretier
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[*] posted on 24-5-2010 at 05:09


Is it prossible to monomethylate toluhydroquinone by the same way? Yes, right?

What's the product? 2-Methoxy- or 5-methoxytoluene or a mixture?

[Edited on 24-5-2010 by Methansaeuretier]
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turd
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[*] posted on 25-5-2010 at 01:32


Yo, in the thread referenced in the first posting of this thread Nicodem posted a mechanistic interpretation of this reaction. Accordingly you will have to use toluhydroquinone as reactant and toluquinone as catalyst. Since both expected products are quite different, you will get one in excess, the question is by how much. If you have access to the necessary analytics, this would be a very interesting experiment. There is a Japanese patent in which a similar reaction is performed, but unfortunately I can't read it. :-P
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turd
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[*] posted on 9-6-2010 at 10:54


Update: The beta,2-dimethoxy-5-ethoxy-beta-phenylethylammonium acetate was brominated in AcOH and distilled to get a slightly yellow oil of beta,2-dimethoxy-4-bromo-5-ethoxy-beta-phenylethylamine. Isolation of the HCl salt and recrystallization from IPA afforded a pure product (structure confirmed) with a melting point of ~194°C (with decomposition).

Yields were terrible, among other things because my distillation gear is not suited for such small-scale work.

In any case, I hope I have shown that BOx type compounds are easily accessible in a home-lab setting. Maybe one day a better preparative chemist with the ability to resolve enantiomers will explore the "provocative pharmacology" (Shulgin PIHKAL #13) of this class of coumpounds. :)
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Ullmann
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[*] posted on 12-6-2010 at 03:41


Good work Turd!

Was the distillation of the freebase really necessary? Recrystallisation of the hydrochloride would not have being sufficient?

I think your amine did catch CO2 from the air and made the carbonate salt.... It is described for certain amine.

Anyway thank you for sharing the good work!

Best Regards,

Dr Ullmann

[Edited on 12-6-10 by Ullmann]




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turd
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[*] posted on 13-6-2010 at 04:27


Thank you, dottore.

Yes, yields probably would have been higher without distillation, especially after bromination. But if it is possible I prefer distillation to recrystallization because it means less experimenting around with solvent systems, temperature, etc. Anyway, got a little less than 1 g, that should be enough for some initial experiments into the BOx area.
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