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Hello everyone,

I'm stuck on a reaction mechanism involving a Curtius rearrangement. No matter how I try I can't seem to recreate it. I found the reaction in a paper I'm supposed to write about. I've asked several of my friends but none of them could figure out the mechanism. I've attached all the information the paper gives about the reaction.


DPPA (Diphenylphosphoryl azide), Et₃N and toluene are used for the rearrangement
HCl and H₂O are used for the hydrolysis.

[pgk]

It is not your fault because the mechanism of the Curtius rearrangement is generally not clearly described in textbooks and websites.
Anyway, the mechanism of Curtius rearrangement is described in the links, below:

Curtius Rearrangement, BYJU’S
https://byjus.com/chemistry/curtius-rearrangement/
File:Curtius rearrangement mechanism v1.svg
https://commons.wikimedia.org/wiki/File:Curtius_rearrangement_mechanism_v1.svg

The so formed acylazide is isomerized to alkyl isocyanate that is hydrolyzed to carbamic acid, which is very unstable and leads to the corresponding amine via liberation of CO2, in situ.

Question: What is the product of hydrolysis of your chemical 1-acylazide derivative?

[Adbrite]

Thank you for your reply and the sources.

The product after hydrolysis is supposed to be "Chemical 2" I posted in the OP which makes it so confusing because I see no way to synthesise it using the method described in the paper.

I suppose it would be helpful if I just posted a link to the paper in question.

https://www.sciencedirect.com/science/article/pii/S0040403902008572

[pgk]

Answer:
The product after hydrolysis is the corresponding amine of the Chemical 1, which is isomerized to the corresponding ketimine under acidic conditions and which is hydrolyzed in situ, to the corresponding ketone (chemical 2).

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Thank you so much!

[pgk]

You are welcome.