[celesfr]

Hi!! i can't solve this, please *delete me*


how can i turn Benzaldehyde into Dibenzyl aniline??

[Jorriss]

Can you also use aniline? If so, aniline can be your nucleophile, and benzaldehyde the electrophile and if you remove water from the reaction...

[AWK]

http://www.chemsynthesis.com/base/chemical-structure-24248.html

[celesfr]

yes, i tried using aniline + benzaldehyde, but i'm getting the imine.
i don't know how to add the extra benzaldehide!
thanks for the answer!

[sjb]

What kind of reaction converts C=N to CH-NH?

[celesfr]

H4LiAl, but i'm trying tp add another benzaldehyde

[Jorriss]

Couldn't add BaCNBH3 after you get the first imine, then add that to a new solution of benzaldehyde?

[celesfr]

ok, so I would get an amine from de imine. if I add benzaldehyde the reaction would just happen? I mean the new amine + benzaldeyde. Or another reagent is necessary?

[Jorriss]

ok, so I would get an amine from de imine. if I add benzaldehyde the reaction would just happen? I mean the new amine + benzaldeyde. Or another reagent is necessary?

So, here's how I think it would occur.

Anniline + Benzaldehyde - H2O = imine

Imine + mild reducing agent = amine

Rinse repeat.

[celesfr]

thank you for answering! but i still have a doubt.
you say:

   Anniline + Benzaldehyde - H2O = imine

   Imine + mild reducing agent = amine (*)

   Rinse repeat.


But if a repeat, the new amine (*) would be a secondary amine, so i wouldn't be able to make another imine (I believe you need an aldehyde/ketone and a primary amine to make an imine).
Thanks!!!

[Doc Oc]

Are you actually trying to make this molecule or is it a theoretical question for a course?

If you're actually trying to make it, use aniline and benzyl bromide with Et3N or similar base.  It doesn't over-alkylate, it will stop after double benzylation.

If it's for a course, then you can do the reductive amination of benzaldehyde and aniline, then add benzyl bromide and base.

[celesfr]

Thank you very much!!!!
It was a theoretical question for an exam i have on Monday.
Wish me luck 

[Jorriss]

thank you for answering! but i still have a doubt.
you say:

   Anniline + Benzaldehyde - H2O = imine

   Imine + mild reducing agent = amine (*)

   Rinse repeat.


But if a repeat, the new amine (*) would be a secondary amine, so i wouldn't be able to make another imine (I believe you need an aldehyde/ketone and a primary amine to make an imine).
Thanks!!!

As someone else said, use benzyl bromide. Reduce benzaldehyde to an alcohol then add POBr2 or something similar.

But if you add your secondary amine to benzaldehyde you'll get an enamine, which can also be reduced.

[408]

1) Benzaldehyde + benzyl amine, reductive amination to dibenzyl amine.
2)  dibenzyl amine + bromobenzene +Pd(0) catalyst +base => product

or
2)dibenzylamine --> the N-lithiated species with some lithium base.  react with PhCu(CN)Li.LiCl and chloranil or IBD.