Sciencemadness Discussion Board

Drying Acetone with Molecular Sieves - condensation products?

FireLion3 - 17-3-2018 at 16:21

I'm finding mixed information on this. One source says never use MS to dry acetone because condensation products will be in abundance, due to MS being slightly basic, although they don't state how long the acetone was let to sit with the MS. Another source says Acetone can be dried just perfectly with molecular sieves without problem.

I'm wanting to condense Acetone with an Aliphatic Amine and use MS to drive the reaction forward, but I'm faced with the potential issue of difficult to remove condensation products. While the condensation should happen rapidly in the presence of sieves, I am unsure if the Acetone-Acetone condensation would take priority.

Bert - 17-3-2018 at 17:24

Recent advice on this, given by member Dr. Bob-


Be aware that drying acetone for too long (much more than a day) can drive the aldol reaction of it with itself forward, as that gives off water and removing the water drives the equilibrium to the right.

FireLion3 - 17-3-2018 at 18:06

With any luck, the condensation with the amine will be faster than the acetone condensation, and since they'll only be in equimolar amounts in a dilute solution, the acetone by products should hopefully be minimized. Ill have to run TLC to track it.