[kriggy]

Hi again
Im here with (another) synthetic exercise question(s) and Im struggling with this structure motiff:


(both of the nitrogens are further alkylated)
Could it be formed from δ-lactam by reaction with amine or am I screwed and have to redo-my synthesis?
(Honestly I think that forming this from δ-lactam is kind of sci-fi but since I almost have it I have to ask )

[Mellitic]

Sorry, I don't know anything about making Schiff bases from amides (as far as I know, it doesn't happen).  I wanted to point out, however, that an endocyclic double bond is going to be more stable than the exocyclic bond, so you will have isomerization of your drawn compound.  You could make that isomer from the Schiff base of the ester, and then displace your alkoxy group with an amine.

[Dan]

It should be possible, but you may need to do a dehydration/activation step separately or other workaround strategy.

The functional group is an amidine, see for example:

http://www.organic-chemistry.org/synthesis/C2N/amidines.shtm

[kriggy]

Dan: thank you, I couldnt find the name of this functional group so it reminded me kind of shiff base

Mellitic: Thank you, this was just a part of the whole compound I needed to figure out or do it all again 

[orgopete]

The imidoyl chloride should be accessible. I suggest reviewing pyrimidone syntheses to determine which strategy you might want to use to deliver the nitrogen.

[kriggy]

Yea those heterocycles and their names, it will be my doon one day :-D Thank you orgo, I´ll look into that

Anyway my current approach to the right half of the molecule, I think I have the other half figured out.

[Archer]

Sorry, I don't know anything about making Schiff bases from amides (as far as I know, it doesn't happen).  I wanted to point out, however, that an endocyclic double bond is going to be more stable than the exocyclic bond, so you will have isomerization of your drawn compound.  You could make that isomer from the Schiff base of the ester, and then displace your alkoxy group with an amine.

I have x-ray data on similar compounds (HCl salts) and the bond lengths of the endo and exocyclic C-N bonds are statistically indistinguishable.

I have not sought the opportunity to investigate the freebase but when you consider the role that the nitrogen lone pair plays in amides I wonder whether resonance between the two could see similar lengths for both in the freebase form.

[orgopete]

Re: scheme

You need to count your carbons, your "X" group looks problematic unless it is the rest of your target. I don't think you need thionyl chloride to cyclize the ring. Getting your amide and amide vinylog to condense will be a problem. Just use an imidoyl chloride instead.

[kriggy]

X was just halogen or suitable leaving group which would be then connected to the rest of the molecule by alkylation of substitued piperidine.  I didnt have time yet to look into the imidoyl chloride way but I will do it asap.
Thanks for help