soma
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imidazole
I was going to be using imidazole in an amino acid synthesis.
Anyone had experience using this compound? Anything I should know other than what is listed in the MSDS?
Thanks.
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MeshPL
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I don't have practical experience with organic compounds but...
Could you please post reactions you plan to do? Using imidazole as an aminoacid production substrate sounds quite iteresting, (unless you just plan to
make histidine).
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soma
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Direct preparation of primary amides from carboxylic acids and urea using imidazole and microwave.
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MeshPL
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Oh... you just plan to make an amide group-containing aminoacid?
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UC235
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I assume this is the relevant literature which should have been linked in the original post. http://www.cs.gordon.edu/~ijl/_lead_papers/Direct%20amidatio...
Carboxylic acids have been shown elsewhere on this forum to form amides in a urea melt without need for microwave heating or imidazole catalyst. Other
papers seem to suggest that pyridine or even TEA can work. If the yield improvement is worthwhile is another question, though if imidazole allows a
lower reaction temp purification may be improved by reducing formation of urea condensation products.
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soma
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Yes - that is the link. I didn't post it because I'm looking for someone who has experience using imidazole and I had already posted that link in a
recent post under a different subject to this forum. I had no problem posting it if someone showed further interest.
Would you have the links to the discussions you mentioned concerning carboxylic acids to amides using urea? I tried doing a search using those terms
but it didn't turn up.
The MSDS makes imidazole sound unpleasant, but MSDSs tend to do that. I'm wondering if it's similar to say, NaOH or KOH in hazard potential.
From the article:
| Quote: | Imidazole was used in this reaction because previously
it has been demonstrated that this compound shows
useful promotion ability
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and forms polar carboxylic
acid salts for efficient microwave energy absorption.
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The promotion ability of imidazole was attributed to
the low melting point of imidazolium carboxylate salts
which melt after heating at low microwave power and
short irradiation time and homogenize the reaction
mixture in dry media.
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Instead of imidazole we used
other bases such as 4-dimethylaminopyridine (DMAP),triethylamine and 1,8-diazabicyclo[5,4,0]undec-7-en
(DBU), but none of them acted as well as imidazole. |
[Edited on 14-10-2015 by soma]
[Edited on 14-10-2015 by soma]
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