There are several different reactions that can be utilized in order to end with a product that includes the synthesis of carbon-carbon bonds, however for this experiment the reaction that was utilized is aldol condensation. An aldol condensation is when an enolizable aldehyde or ketone undergoes a reaction, in the presence of a base or acid, and gives a beta unsaturated ketone or aldehyde (Utah Valley University, 2009). This type of reaction can also add carbonyls to a compound, using similar methods to the Grignard reaction. It is also important to note that in order for this reaction to occur, an alpha hydrogen must be present on one of the reagents (Farmer, 2013). In the following experiment, dibenzalacetone is synthesized using aldol condensation.
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Then take and initial TLC, and allow the mixture to react for 30 minute, while occasionally shaking. After the time is up take another TLC, setup a steam bath for later, and remove the liquid from the test tube using a pipette. Next add three mL of water to the test tube, shake, and remove the liquid- do this step three times. Then remove the crystals using a Hirsch funnel and recrystallize it using a mixture of 70:30 ethanol and water. Add a boiling stone to help with boiling and place tube in steam bath till solid is dissolved. Once solid is dissolved allow mixture to cool and remove crystals via filtration, wash crystals with 70% cold ethanol, calculate percent yield, and perform IR. The experimental melting point of dibenzalacetone was 95-100°C and its literature melting point is 110.5-112°C. Possible explanation for the difference in melting point could be that there is the presence of impurities in the final product, or that it was still wet when the melting point was being conducted making it melt more quickly. The theoretical yield for dibenzalacetone was 0.45g, but the actual yield was 0.257g making the percent yield 57%. Rf was also calculated and this helped keep track of the progression of the reaction. The first Rf contained 4 different compounds, which means the reaction still contained starting materials and was not complete, but the second Rf shows only one compound, which is the final product. The IR spectrum helps identify what functional groups are present in the product and the experimental IR indicates that the product that was obtained is not dibenzalacetone. There is suppose to be s strong peak at 1700 cm-1 to indicate the ketone, but there isn’t and also there seems to be the presence of an alcohol, which could be the
Then take and initial TLC, and allow the mixture to react for 30 minute, while occasionally shaking. After the time is up take another TLC, setup a steam bath for later, and remove the liquid from the test tube using a pipette. Next add three mL of water to the test tube, shake, and remove the liquid- do this step three times. Then remove the crystals using a Hirsch funnel and recrystallize it using a mixture of 70:30 ethanol and water. Add a boiling stone to help with boiling and place tube in steam bath till solid is dissolved. Once solid is dissolved allow mixture to cool and remove crystals via filtration, wash crystals with 70% cold ethanol, calculate percent yield, and perform IR. The experimental melting point of dibenzalacetone was 95-100°C and its literature melting point is 110.5-112°C. Possible explanation for the difference in melting point could be that there is the presence of impurities in the final product, or that it was still wet when the melting point was being conducted making it melt more quickly. The theoretical yield for dibenzalacetone was 0.45g, but the actual yield was 0.257g making the percent yield 57%. Rf was also calculated and this helped keep track of the progression of the reaction. The first Rf contained 4 different compounds, which means the reaction still contained starting materials and was not complete, but the second Rf shows only one compound, which is the final product. The IR spectrum helps identify what functional groups are present in the product and the experimental IR indicates that the product that was obtained is not dibenzalacetone. There is suppose to be s strong peak at 1700 cm-1 to indicate the ketone, but there isn’t and also there seems to be the presence of an alcohol, which could be the