Comments on: The Hofmann and Curtius Rearrangements https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/ Wed, 21 Sep 2022 09:27:57 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: 7 Tips to ace organic chemistry in NEET/JEE | Science tidings https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-600430 Sun, 02 May 2021 17:46:29 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-600430 […] Hofmann and curtius rearrangements […]

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-577758 Mon, 09 Mar 2020 20:46:19 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-577758 In reply to Prahlad.

Not sure. Heating with Br2 and KOH is usually what you’d do with an amide (Hofmann rearrangement conditions), not an acyl azide. Eventually the heat should lead to a Curtius rearrangement, but I’m not sure what the effect would be. There’s no reason to add Br2 and KOH to an acyl azide.

]]> By: Prahlad https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-577742 Mon, 09 Mar 2020 15:03:41 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-577742 Sorry what happens if I heat acyl azide with aq KOH and Br2?

]]> By: Prahlad https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-577741 Mon, 09 Mar 2020 15:00:38 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-577741 What happenes when an isocyanate is heated with aq KOH+Br2?

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-563875 Thu, 12 Sep 2019 20:44:54 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-563875 In reply to Peter.

Shoot. You are correct. Thanks for spotting, fixed.

]]> By: Peter https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-536276 Mon, 06 Aug 2018 00:03:25 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-536276 Hi, there appears to be a “typo” in the Part 1 image for the acyl azide: the “plus” charge should be on the middle nitrogen instead of the nitrogen bonded to the oxygen? Googling “acyl azide” seems to confirm what the correct charge distribution for acyl azide looks like.

]]> By: James https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-535528 Mon, 16 Jul 2018 19:49:46 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-535528 In reply to SWAPNIL.

Great question. You need a primary amide. If you try to perform it with a secondary amide you just end up replacing N-H with N-Br and it stops there, since there’s no N-H for the HO- to deprotonate and no driving force for the reaction.

]]> By: SWAPNIL https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-535414 Sat, 14 Jul 2018 05:34:03 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-535414 Hi James,
Thank you for sharing such a great explanation. However, I am wondering is it possible to have some change in an amide. Instead of CO-NH2 if we use CO-NHR will it result in the same rearrangement?
Thanks in advance James, you are the best!

]]> By: PMT help-Tips to learn organic chemistry. – Hello! I am Sriharsha Koduru https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-534202 Sat, 16 Jun 2018 13:36:58 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-534202 […] Hofmann and curtius rearrangements […]

]]> By: Ben https://www.masterorganicchemistry.com/2017/09/19/hofmann-and-curtius-rearrangements/#comment-522955 Sun, 12 Nov 2017 02:11:03 +0000 https://www.masterorganicchemistry.com/?p=11006#comment-522955 In reply to James.

Thanks for taking time to respond. I had it in mind that the pKa of amides was approximately 25, but it seems I wasn’t accounting for the solvent since I got this value from the Bordwell table (in DMSO).

Warmest regards,

Ben

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