iloveloli
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amide and nitrous acid?
just like the topic, adding nitrous acid to amide.
will they form acyl cation (acylium ion)??
i am thing that lf acylium ion can react with benzene-- likeFriedel–Crafts reaction
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Metacelsus
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Short answer: no, it won't.
Long answer: the reaction products depend on whether it's a a primary, secondary, or tertiary amide.
A tertiary amide won't react.
If it's a primary or secondary amide, a nitrosamide will be formed. If it's primary, it will decompose to a carboxylic acid with formation of nitrogen
gas. If it's secondary, it may be stable. A secondary nitrosamide can be used to form a diazo compound.
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DJF90
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Quote: Originally posted by Cheddite Cheese  | Short answer: no, it won't.
Long answer: the reaction products depend on whether it's a a primary, secondary, or tertiary amide.
A tertiary amide won't react.
If it's a primary or secondary amide, a nitrosamide will be formed. If it's primary, it will decompose to a carboxylic acid with formation of nitrogen
gas. If it's secondary, it may be stable. A secondary nitrosamide can be used to form a diazo compound. |
Whilst you're correct that the reaction pathway depends upon the degree of substitution of the amide nitrogen, I don't agree that the acylium ion is
not involved in the case of primary amides. How do you think the hydrolysis of 1* amide to carboxylic acid works mechanistically if the acylium
species is not an intermediate?
I'm not sure you could get it to participate in the Friedel-Crafts reaction though. You're generating (at least) one equivalent of water during the
nitrosation reaction which will be a competitive nucleophile. Add to that the fact that any arene activated enough to compete with that water will
also react with the nitrosating reagent, and you're probably not going to get very far.
[Edited on 15-2-2016 by DJF90]
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Metacelsus
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I was thinking that the primary nitrosamide would decompose by hydrolysis (after all, water will be present in the nitrosation, as you stated)
directly to the carboxylic acid and nitrous amide (NH2NO); the nitrous amide would then immediately decompose to nitrogen gas and water.
I might be wrong about this, however.
Edit: Maybe you could get around hydrolysis by using N2O3.
[Edited on 2-15-2016 by Cheddite Cheese]
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Nicodem
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A related topic: Acid halides from amides
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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