Aldol Condensation Reaction Mini Lab

Kiki Yetman
CHEM 2125-003
Dr. Sri Satyan
12/5/14
                                Aldol Condensation Reaction Mini Lab

Objective: To select a combination of aldehyde and ketone to learn about the structure and reactivity of aldol condensation reactions.

Materials Required: Test tube, 2 mmol cyclopentane, 4.0 mL ethanol, 8.0 mmol t-cinnamaldehyde, 3.0 mL 1M NaOH, 2 mL 95% ethanol, 2mL  4% acetic acid, ice bath, filtration set up, melting point apparatus.

Discussion:  Aromatic aldehyde react with ketones in the presence of a base to form aldol-type condensation products. In the presence of excess aldehyde each mole of ketone can condense two moles of the aldehyde.

[pic 1]

Procedure: Select one aldehyde and one ketone from the given list. Acciurately measure 2.00 mmol of the ketone and put it into a test tube. Add 4.0mL of 95% ethanol to dissolve it. Stir in 8mmol of the aldehyde and 3.0 mL of 1M NaOH. Let reaction sit at room temperature for 10min, shaking occasionally. Cool mixture down further in an ice bath. Collect the aldol condensation by vacuum filtration, washing it on the filter with 2mL cold 4% acetic acid, then with 2 mL of 95% ethanol. Dry then measure its mass and melting point.

Observations:  

• When first mixed, t-cinnamaldahyde with 4.0 mL of 95% ethanol, solution appeared oily
• precipitate formed immediately when 1M NaOH was added.
• The formed precipitate is mustard yellow and quickly the whole solution solidified.
• Test tube felt warm to the touch
• smells like cinnamon
• yield produced 0.67g of product
• melting occurred between 115 and 225 C

[pic 2][pic 3][pic 4]

Conclusion: From our reaction, we formulated this mechanism. The actual melting point is 220 so our sample was mostly pure.[pic 5]