Hey guys doing an Icaridin synth, stuck on intermediate. Trying to get from Piperidine(CH2)5NH) to 4-Piperidone(C5H9NO)

[ShaneS]

I know there are easier routes but the route below would enable a completely green synth starting from black pepper(which would be great for the insecticide industry to have it come from black pepper extract(piperine --> piperidine(or piperic acid) --> piperidone) from a marketing and environmental perspective. Also has tremendous application in Southern Africa due to rising import costs etc. Anyway pls feel free to ask anything(it's job related and I really need the help and I'm not getting anywhere myself inorganic chemistry is more my forte but I'm trying. I don't know how you guys just know this stuff like "oh just add a carbonyl group with some duck-tape". Make it seem so easy...

The goal is to get from:

 To this:

 

Thanks so much in advance.

 

 

 

 

Edited December 27, 2021 by ShaneS
addition of images

[exchemist]

34 minutes ago, ShaneS said:

I know there are easier routes but the route below would enable a completely green synth starting from black pepper(which would be great for the insecticide industry to have it come from black pepper extract(piperine --> piperidine(or piperic acid) --> piperidone) from a marketing and environmental perspective. Also has tremendous application in Southern Africa due to rising import costs etc. Anyway pls feel free to ask anything(it's job related and I really need the help and I'm not getting anywhere myself inorganic chemistry is more my forte but I'm trying. I don't know how you guys just know this stuff like "oh just add a carbonyl group with some duck-tape". Make it seem so easy...

The goal is to get from:

 To this:

 

Thanks so much in advance.

 

 

 

 

Golly, you need a professional synthetic chemist, I think. It's 40 years since I did this sort of thing, and then only as a paper exercise. Maybe try the local university organic chem dept? 

But out of pure interest (it being Christmas), and to start the ball rolling, I did a few searches. It looks as if you can convert piperidine to the cyclic imine, via treatment with calcium hypochlorite to make the N-chloro derivative, followed by dehydrohalogenation. This could be a start. It seems there are ways to "walk" the double bond along hydrocarbon chains, using an Ni catalyst.  If you could get the double bond to the 3,4 position via a walk of 2 steps, you would be in with a chance of adding water across the double bond to make the alcohol, which you could then oxidise.  But I've no idea of whether this walking would work with an imine rather than a hydrocarbon or how you would control the products to get the one you want.

Maybe someone else here can comment.