Sciencemadness Discussion Board

Dean Stark - Separating Acetone & Water? What?

GreenD - 11-6-2013 at 16:00

"Investigations on heterogeneously catalysed condensations of glycerol to cyclic acetals"

The magnetically stirred (1000 rpm) reaction mixture (glyc-
erol, aldehyde or acetone, solvent, and catalyst) was refluxed in a 100-mLflask with a condenser. A Dean–Stark trap was used to remove the formed water continuously.


They use the following reaction scheme:

Reaction mixture for the acetalisation of acetone: 0.1 mol glycerol, 0.15 mol acetone, 17.5 ml refluxing dichloromethane, 0.5 g Amberlyst-36 as the catalyst. The given yield is related
to glycerol.


This is for the preparation of soketal

... Am I to assume that Water will form a layer, while acetone/DCM/soketal will form another?

Seems a bit odd to me, that removal of water is going to remove copious amounts of acetone... Make sense to anyone?

This seems to be the main reaction to produce soketal with the use of acetone.

Organikum - 11-6-2013 at 16:50

Water removal by the DCM/water azeotropic system maybe?

GreenD - 12-6-2013 at 09:30

Ran the expt verbatim, however only had a http://www.rightpricechemicals.com/media/catalog/product/cac... to separate water.

End up with dark nasty on the bottom, no separate layers on the top.