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Aldol Condensation : An Experiment

Satisfactory Essays

Aldol Condensation
2 March 2017
Delaney Griffin
Ron Hickman

Abstract: This experiment used Aldol Condensation, more specifically, double Claisen-Schmidt condensation in order to synthesize dibenzalacetone from benzaldehyde and acetone. In part one of the experiment, an aldol reaction occurred. In part two of the experiment, the product was recrystallized. The results concluded that the percent yield of dibenzalacetone was 82.80%. The melting point range of the product was 106.5 °C -109.3 °C due to the difficulty of boiling out the ethanol and therefore resulted in an impure solution. Overall, the experiment successfully resulted in the synthesis of dibenzalacetone, as well as, investigation of the characteristics of the product. …show more content…

During the first step of the reaction, acetone forms an enolate. An enolate ion, is “a resonance structure of the carbanion in which the negative charge is on an oxygen atom” (Kady 55). Due to the lack of an alpha hydrogen, the benzaldehyde acts as the carbonyl group. The acetone attacks the benzaldehyde and forms the aldol product. It then undergoes dehydration to result in the final product- an unsaturated ketone. Aldol condensation is an important type of organic synthesis used in a multitude of ways. The product found in this experiment, dibenzalacetone, can be useful for a variety of different things. For example, it is “commonly selected as sunscreen components based on the ability to absorb the full spectrum of UV-A radiation” (Chemicals & Chemistry).

Figure 2: The equation above shows the condensation reaction between benzaldehyde and acetone that occurs throughout the experiment in order to produce dibenzalacetone. This type of Claisen-Schmidt condensation varies from typical aldol condensation (Kady 57).

Acetone
Benzaldehyde
Ethanol

Figure 3: Above, are the chemical structures of some of the reagents used throughout the experiment.

Experimental: First, 1.5 mL of ethanol and 2 mL of 10% NaOH was placed in a test tube. In a glass vial, 0.21 g of benzaldehyde and 0.06 g of acetone were mixed. This mixture was added with a pipette in three proportions to the test tube. Between each addition, two

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