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Topic: Mechanism of Hofmann Rearrangement for phthalimide  (Read 1788 times)

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Offline CaRRo

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Mechanism of Hofmann Rearrangement for phthalimide
« on: December 18, 2020, 04:37:47 PM »
Hello guys!

I have a problem with writing correct mechanism of Hofmann Rearrangement for phthalimide. Somebody Can tell me what's wrong with this save? My teacher say that's wrong and I have no idea how fixed it.


Offline AWK

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #1 on: December 18, 2020, 05:31:30 PM »
The primary problem was the pre-hydrolysis of the phthalimide. The rest of the mechanism is in every textbook.
AWK

Offline CaRRo

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #2 on: December 18, 2020, 06:04:06 PM »
The primary problem was the pre-hydrolysis of the phthalimide. The rest of the mechanism is in every textbook.

Thank You for answered. Not exactly in every textbook. Can you give me some title of textbook in which Can I find this? Please.

Offline rolnor

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Offline AWK

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #4 on: December 19, 2020, 03:55:36 AM »
It is a good practice that a professor (instructor, teacher) recommends a textbook that contains most of the required material. In addition, supplementary literature is provided.
You can also find many good sources on the Internet (mainly University sources, dedicated portals, e.g. Name-reaction, com, Organic Chemistry Portal, Wikipedia, etc.).
When writing any reaction mechanism one must remember about all electrons and charges (at least for atoms participating in the reaction mechanism), which is missing from the diagram. e.g. there is no electron pair on nitrogen in structures 1, 2, 3 and 4, additionally in structure 4 there is no negative charge on nitrogen.
Therefore, my advice was to start with the initial hydrolysis to phthalamic acid. Maybe CaRRo would notice his mistakes?
AWK

Offline amphotericinb

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #5 on: December 28, 2020, 07:58:12 PM »
The primary problem was the pre-hydrolysis of the phthalimide. The rest of the mechanism is in every textbook.

Thank You for answered. Not exactly in every textbook. Can you give me some title of textbook in which Can I find this? Please.

If you google Hofmann Rearrangement, wikipedia has a vivid mechanism. you can check there.
Hofmann Rearrangement is known to be able to turn amide into amine, losing 1 carbon.

Offline amphotericinb

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #6 on: December 28, 2020, 08:03:42 PM »
https://en.wikipedia.org/wiki/Hofmann_rearrangement

Exactly, they draw the mechanism well.

Better explained even than my former text book

Offline AWK

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Re: Mechanism of Hofmann Rearrangement for phthalimide
« Reply #7 on: December 29, 2020, 07:40:22 AM »
I do not recommend the Wikipedia mechanism for novice chemists, and such chemists mainly have problems with reaction mechanisms. The mechanism at: https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Reactions/Named_Reactions/Hofmann_rearrangement
is much better. because it contains all the electrons and charges. Of course, for phthalimide, this mechanism has to be adjusted by adding partial hydrolysis.
AWK

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