ergoamide
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Pyridine Substitute
I did ask this forum on another forum but it's down at the moment and i can't recall what all the listed substitutes for a standard acylation of an
amine to amide using acyl chlorides. Normally pyridine is used and i remember something about DMAP being the best to use but it was hard to separate
out being the end product is an amide. Does anyone else know any other substitutes?
Ergo
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Nicodem
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Any tertiary amine will do more or less fine for most acylations of amines with acyl chlorides. Even K2CO3 works as HCl scavanger but then the
reaction medium is heterogenous.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
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jon
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how does an aportic base like this work to catalyse acylations of alcohols and amines when using acid anhydrides?
can sodium acetate be used or does this serve as a buffer against the carboxylic acid produced in the reaction?
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Nicodem
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Unlike few less reactive nucleophiles like some stericaly hindered alcohols and similar, the acylation of amines with acyl chlorides requires no
catalysis. The bases here are used to allow the reaction to go to completition by scavenging the formed HCl and not for catalysis.
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ergoamide
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Thanks heaps nicodem, i was told that they acted as a catalyst so assumed that their purpose was not really to scavenge HCl. If using K2CO3 strong
stirring would overcome the disadvantage of the mixture being hetergenous wouldn't it?
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solo
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Reference Information
Chemoselective Acylation of Amines in Aqueous Media
Sarala Naik, Gitalee Bhattacharjya,Bandana Talukdar and Bhisma K. Patel
Eur. J. Org. Chem. 2004, 1254 1260
Abstract
Amines are efficiently acylated by both cyclic and acyclic anhydrides by dissolving them in an aqueous medium with the help of a surfactant, sodium
dodecyl sulfate (SDS). Cyclic and acyclic anhydrides react with equal ease with an amine, and amines with various stereo-electronic factors react at
the
same rates with an anhydride. Chemoselective acylation of amines in the presence of phenols and thiols and of thiols in the presence of phenols has
been achieved. No acidic or ba- sic reagents are used during the reaction. No chromatographic separation is required for isolation of the acylated
products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by-products make the present method a green chemical
process.
Keywords Amines / Amides / Acylation / Aqueous media / Chemoselectivity
Note: It is well known that NaBH4/I2 or H2SO4 or NiCl will reduce the acylated amine .....to the methylated amine...will this also occur with this
various anhydrides used in this study?
Attachment: Chemoselective Acylation of Amines in Aqueous Media.pdf (150kB)
This file has been downloaded 1103 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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solo
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Reference Information
Convenient, Cost-Effective, and Mild Method for the N-Acetylation of Anilines and Secondary Amines
H. S. Prasad; G. R. Srinivasa; D. Channe Gowda
Synthetic Communications,Volume 35, Issue 9 May 2005 , pages 1189 - 1195
Abstract
An efficient, cost-effective, and mild method for the N-acetylation of anilines and secondary amines with ammonium acetate in acetic acid media at
reflux temperature in good yield is described.
Keywords N-Acetylation; ammonium acetate; anilines; secondary amines
[Edited on 4-7-2007 by solo]
Attachment: Convenient, Cost-Effective, and Mild Method for the N Acetylation of Anilines and Secondary Amines.pdf (92kB)
This file has been downloaded 3806 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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