[Nescafe]

Hi,

Does anyone know  a good procedure on converting a primary C-X (MOLECULE - phenylCH2Br) to a primary amine (MOLECULE - phenylCH2NH2). Functionalities on the rest of my compound to watch out for (I.e. MOLECULE):

Few benzyl protecting groups
An amide bond

Cheers,

Nescafe.

[discodermolide]

Hi,

Does anyone know  a good procedure on converting a primary C-X (MOLECULE - phenylCH2Br) to a primary amine (MOLECULE - phenylCH2NH2). Functionalities on the rest of my compound to watch out for (I.e. MOLECULE):

Few benzyl protecting groups
An amide bond

Cheers,

Nescafe.

You can use ammonia, but you will end up with mixture of secondary and tertiary amines, because the benzylamine is more reactive and will react with the benzyl bromide.
Best to use t-Butylcarbamate, then you can easily remove the Boc group later. And the side reactions should not happen.
You can also use sodium azide, get the benzyl azide and reduce the azide to the amine.
I have a procedure for the halide to azide conversion but I need to translate it from German.

[nox]

The azide + reduction combo seems the best way to go.

[Dan]

Agreed, I've gone through the azide many times. It can be reduced by a variety of methods: catalytic hydrogenation, dissolving metal reduction (including mild protocols like Zn/NH₄Cl, and Zn/CuSO₄/AcOH), Staudinger reduction, sodium hydrogen Telluride (NaBH₄/Te), dichloroindium hydride (InCl₃/silane), and probably many more.