Sciencemadness Discussion Board

Pd/C (+H2) Catalyzed Reductive Amination of Aliphatic Ketones

qt314 - 25-4-2019 at 03:29

I would like to report my success with palladium catalyzed reductive aminations of phenylacetones using acetate salt of amines and 1atm Hydrogen atmosphere.
Conditions

1.3 mol amine is mixed with 600ml methanol and cooled to 0degC.
1.3 mol acetic acid is added and the pH is adjusted to ca. 6.
1 mol ketone is added and the mixture is stirred in the cold for 60 minutes.
0.013 mol palladium supported on carbon is added.
Atmosphere is removed and replaced with hydrogen.
Stirring is continued until hydrogen absorption stops or slows down considerably (12-24 hours).
The mixture is then filtered through a plug of celite, washed with methanol and water.
1200ml water are added to the mix and pH adjusted to 12-13.
The mixture is extracted 3 times with dcm or other non polar; non polar washed with water, brine and dried with sodium sulfate.
The solvent is evaporated to afford the target amine in good to excellent yields.

So far mdp2p yielded with:
Methylamine - 82%
Ammonia - 74%

p2p yielded with:
Methylamine - 80%
Ammonia - 67%
Ethylamine - 86%

Hope this helps somebody :)

chemistry007 - 25-8-2019 at 00:20

Does it works without pressure? only 1 atm?