Matthew McBride


To recrystallize trans-dibenzalacetone from ethanol using the sintered glass funnel method


A 0.74 M solution of trans-dibenzalacetone in ethanol was created in a 10 mL test tube and dissolved at 75°C of ethanol using a water bath. The crystals were cooled to room temperature, vacuum filtered using a sintered glass funnel and dried over air.


Recrystallization Sheet
Concentration: 0.74 M
Amount of Product: 0.1787
Yield: 69%


For a 0.74 M solution, the crystals were predicted to dissolve into the solution at 65°C and were observed to enter the solution around 75°C.

The predicted recrystallization yield for dibenzalacetone in ethanol at the boiling point solubility of 1.29 M and the 25°C boiling point of 0.092 M is 93%. At the solubility of 0.74 M, the predicted recrystallization yield is 87%. The measured recrystallization was lower at 69%.


The recrystallization yield of trans-dibenzalacetone in a 0.74 M solution of ethanol was measured to be 69%.



12:56 0.2600 g of dibenzalacetone from UCEXP285 - Product A was added to a 10 mL screw cap test tube (tube #1).
13:04 0.9925 g of ethanol was added to tube #1 and it was placed in the hot water bath.
13:08 At 75°C, all of the crystals were observed to enter the solution. Tube #1 was removed from the hot water bath and allowed to cool to room temperature.
13:09 Crystals were visible in the solution.
13:38 The weight of the 4 cm diameter sintered glass funnel empty was 34.0049 g. The content of tube #1 was transferred to the sintered glass funnel with an additional 0.5 mL of ethanol used to remove the crystals from the test tube. The vacuum was turned on and the crystals were filtered. The crystals were spread over the surface of the funnel to dry over the vacuum.
13:53 The weight of the empty 5-dram vial was 11.8284 g.
14:18 The funnel was removed from the suction and the weight of the sintered glass funnel with the crystals was 34.0922 g.
14:24 The crystals (Product A) was removed from the sintered glass funnel and placed in the 5-dram vial. This vial weighed 12.0071 g with Product A.