March 28, 2024, 05:26:28 PM
Forum Rules: Read This Before Posting


Topic: Alkylation vs acyl substitution of amide  (Read 2929 times)

0 Members and 1 Guest are viewing this topic.

Offline Doc Oc

  • Chemist
  • Full Member
  • *
  • Posts: 564
  • Mole Snacks: +48/-12
Alkylation vs acyl substitution of amide
« on: January 30, 2013, 02:45:50 PM »
I'm having a strange problem.  I have a linear amide with a primary alkyl bromide.  I am attempting to phenoxylate the compound, but instead I am seeing substitution at the amide and preservation of the bromine!  I've used several different solvent/base combos (DMF, DCM, acetone, Et3N, K2CO3, pyridine, proton sponge) with cooling/heating/neither, none of them giving a different result.  I can't say I've ever seen this happen and I'm rather surprised.  Does anybody have any suggestions on how to solve this?  I'm about at my wit's end.

Offline Dan

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 4716
  • Mole Snacks: +469/-72
  • Gender: Male
  • Organic Chemist
    • My research
Re: Alkylation vs acyl substitution of amide
« Reply #1 on: January 31, 2013, 03:05:03 AM »
That's pretty fruity. What's the amide, something active like an acyl pyrrole?

Not the cheapest solution, but maybe try silver phenoxide - the Ag+ should strongly activate the alkyl bromide.

You could also bulk up the amide.
My research: Google Scholar and Researchgate

Offline Doc Oc

  • Chemist
  • Full Member
  • *
  • Posts: 564
  • Mole Snacks: +48/-12
Re: Alkylation vs acyl substitution of amide
« Reply #2 on: January 31, 2013, 07:56:18 AM »
Morpholine!  I like your suggestion and I should have thought of it since I've used silver salts in challenging alkylations in the recent past.  Thanks for the refresher Dan.

Sponsored Links