jackson2004
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Solvent alternatives
Are there any similar alternative solvents to benzene in the standard synthesis of 4-Methyl aminorex from cyclization of PPA with cyanogen bromide.
Also is there any method of avoiding cyanogen bromide, I have the precursors but want to avoid use of such a dangerous unstable chemical.
Refs please if possible as well, i would like to research well before attempting any new synthesis.
It isn't that i am lazy and cant be bothered to search for information. Its just that i either do not know where to look, or there isn't much
information on such alternatives.
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tr41414
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Hmm... if you can't use google...
Anyways... don't use CNBr...
[Edited on 4-7-2007 by tr41414]
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solo
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| Quote: | Generally one would start by searching the forum with various phrases related to the information wanted.......solo
Try searching for 4-MAR,
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Bandil, the Hive; posted by woden
Practice (in theory of course)
5 grammes of norephedrine.HCl(26,5 mmoles), was placed in a 100 mL FBF, and 2,3 grammes of KOCN(28,4 mmoles) and 25 mL's of distilled water was
immediately added in succession. This was heated to reflux directly on the hotplate for two hours.
After this time, 30 mL's of 2M HCl(60 mmoles) was added. This caused a bit of bubbling(probably from the excess cyanate being broken down to gasseus
-i-cant-remember-what-). Reflux was continued for an additional two hours. The mixture took on an ever so slight pinkish tint, which the "old" synth
also tend to do at this stage.
After 2½ hours of reflux, the mixture was cooled and basified with sodium carbonate and presto a lot of pretty white crystals precipitated on the
bottom of the beaker. The yeild looked like that which is expected from the normal reaction. They will be measured shortly.
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[Edited on 4-7-2007 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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tr41414
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 yes... that is the famous reaction that made ppa go illegal almost anywhere...
Cyanate can be made out of urea and hydroxide  i think the only drawback
(hmm... or it may actually be a plus) is that cyanate will react only with specific stereoisomers to form trans-4-mar
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jackson2004
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Thanks, That looks like an excellent synthesis
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