Ragnarok
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Paraxanthine
I searched the forum and found nothing relevant, searched google and found only med journals, so any help from you guys would be most apreciated 
Here goes: I need the metabolites of caffeine, paraxanthine in particular. All I found is that some enzyme in the liver breaks up caffeine into the
methyl-xanthines, with a preference for paraxanthine (84%... yay!).
Is there any chemical way to do the same thing (get rid of a methyl group attached to a nitrogen) but not more (as in don't go all the way to
xanthine). An alternative would be to go all the way to xanthine and re-methylate selectively, but i somehow suppose that's harder.
The small five membered ring of xanthine looks aromatic to me, so the N-me bound might be stronger (that could explain why it is the least likely to
break).
Please help! I don't want to put fresh pig liver through my blender and use it as a catalyst 
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Ritter
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You should check out these papers:
Mueller, CE et al Synthesis 1998 (10), 1428-1436. It gives a synthesis of paraxanthine.
Schmidt P Helv Chim Acta 1958, 1052-1060. Same comment.
[Edited on 30-7-2008 by Ritter]
[Edited on 30-7-2008 by Ritter]
Ritter
=============================
\"The production of too many useful things results in too many useless people.\"
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Ragnarok
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I should. But I can't. I don't have a subscription to anything and can't afford one. Our school had free access to sciencedirect, but that's gone too.
And a library that has journals newer than the 80's would be impossible to find in my country 
Thanks, anyway!
[Edited on 30-7-2008 by Ragnarok]
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ScienceSquirrel
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This journal looks like it might have a synthesis;
http://www.springerlink.com/content/w5h1273202263125/
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solo
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| Quote: | Originally posted by Ritter
You should check out these papers:
Mueller, CE et al Synthesis 1998 (10), 1428-1436. It gives a synthesis of paraxanthine.
Schmidt P Helv Chim Acta 1958, 1052-1060. Same comment.
[Edited on 30-7-2008 by Ritter]
[Edited on 30-7-2008 by Ritter] |
See the madhatters ftp as many of the synthesis volumes reside there......solo
here is the other reference......
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Heilmittelchemische Studien in der heterocyclischen Reihe. 22. Mitteilung. Pyrazolo-pyrimidine II. Pyrazolo[3,4-d]pyrimidine mit
Koffein-ähnlicher Struktur und Wirkung
P. Schmidt, K. Eichenberger, J. Druey
Helvetica Chimica Acta Volume 41, Issue 4,(p 1052-1060), 1958
Attachment: Heilmittelchemische Studien in der heterocyclischen Reihe. 22. Mitteilung. Pyrazolo-pyrimidine II. Pyrazolo[3,4-d]pyrimi (1.1MB)
This file has been downloaded 636 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Ragnarok
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Thanks guys!
One more thing though... what on god's green earth is the madhatters ftp?
Solo, thanks a lot for the text, i'll try to get someone to translate for me If
I find out how to make this, i'll let you all know.
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solo
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Synthesis of Paraxanthine and Isoparaxanthine Analogs (1,7- and 1,9-Substituted Xanthine Derivatives)
Christa E. Müller, Dirk Deters, Andreas Dominik, Maciej Pawlowski
Synthesis pg.1428, 1998
Abstract:
A general, convenient method for the preparation of
1,7- and 1,9-disubstituted xanthine derivatives (paraxanthine and
isoparaxanthine analogs) was developed starting from 6-amino-2-
methoxypyrimidin-4-one. Alkylation with alkyl halides in acetone/potassium carbonate in the presence of a phase-transfer catalyst
(PTC) yielded an equimolar mixture of N3- and O 4 -alkylatedproducts, which could be separated by dry column chromatography.
The N3-alkylated uracil derivatives were converted to the
corresponding 1-alkyl-2-methoxypurin-6-ones by standard procedures.
PTC alkylation yielded an equimolar mixture of 7- and 9-
alkylated isomers, which were again conveniently separated by
dry column chromatography. The title compounds were obtained
after acid hydrolysis of the 2-methoxy group in satisfactory
yields.
Key words:
paraxanthine, isoparaxanthine, xanthine synthesis,
alkylation, phase transfer catalysis
Attachment: synthesis page 1428, 1998.pdf (71kB)
This file has been downloaded 4038 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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