acid amide and nitrous acid

[jyoticlub]

I am looking forward for the most plausible mechanism of the reaction between acid amide (derivative of carboxylic acid) and HNO2.

although i know the general reaction ar written in my book ie.

 

 

R-CONH2 + HNO2 == (HEAT) == >R-COOH + N2(evolved)+H2O

 

mechanism would hel me identifying which kinds of acid amides and participate in such reactions.

[aviridiane]

 

R-CONH2 + HNO2 == (HEAT) == >R-COOH + N2(evolved)+H2O

 

 

Looking at the final products from the equation, I think the reaction mechanism may be somewhat similar to the reactions of primary amines with nitrous acid

 

So if that's the case, then the mechanism would be something like this:

 

Reagent: sodium nitrite, NaNO2 + HCl (aq)

 

Since the diazonium salts is not stable, it decomposes readily to form nitrogen gas and a carbocation.

 

The carbocation then reacts with water to give the carboxylic acid.

 

Overall equation:

 

I am not really certain, so do correct me if i am wrong.

[jyoticlub]

thanks for your valuable effort the mechanism seems to be correct.

one thing i also wanted to know if u can clear my doubt,

 

 

while drawing the resonating structures of chlorobenzene how can we show partial double bond character on chlorine though it cannot expand its octet?

[Fuzzwood]

It can use one of its free electron pairs, which, in turn, puts a negative charge on the entire ring.