Saturday, May 18, 2019

Diels-Alder reaction Essay

patternIn this experiment a Diels-Alder chemical reaction was used to form the products. Cyclopentadiene and maleic anhydride were reacted to deposither to form cis-Norbornene-5,6-endo-dicarboxylic anhydride. 7-oxabicyclo2.2.1hept-5-ene-2,3-dicarboxylic anhydride was also produced done a Diels-Alder reaction with the combination of furan and maleic anhydride.EquationProcedurePart 1In a flask equipped with a septum side arm and topped with distillation heat and a thermometer tot 2.5ml of mineral anoint. Heat the oil. At the end of the distillation heat puzzle an trumpery filled beaker. When the oil reaches 250C inject 0.6ml of dicyclpentadiene drop wise through septum. Make sure the temperature does not go in a higher place 45C. The product is then(prenominal) weighed.Part 2In a reaction tube place 0.20g maleic anhydride and 1.0ml of ethyl acetate then add 1.0ml of hexane. Then add 0.20ml of cyclopentadiene. Cool the tube in an ice bath. Remove solvent from crystals using pipe tte. Wash crystals with hexanes then remove solvent again. Allow crystals to dry.Part 3In a flask place 2.4g maleic anhydride and add 20ml of diethyl ether. Dissolve mixture using hot casing then let cool to room temperature. Add 1.8ml of furane to the flask. Wrap the flask with Parafilm after placing a stopper on top of flask. Place the flask under the hood for the next lab period. Upon the pay back of the next class period the formed crystals were scrapped from the flask. The crystals were then weighed and melting closures were observed.Discussion and ConclusionA Diels-Alder reaction was used to produce the products of this experiment. The first reaction was cyclopentadiene with maleic anhydride to from the product of cis-Norbornene-5,6-endo-dicarboxylic anhydride. Before that could be produced, dicyclopentadiene had to be cracked to get cyclopentadiene for the starting material. Cyclopentadiene and maleic anhydride were mixed together and cooled to room temperature, which prod uced crystals. The solvent was pipette out of the tube to separate the crystals. The crystals were then scraped on the filter paper to get weight and melting points. The end product throwed 82.6%. The melting point was observed at 162-163C. This indicated a close to pure substance with the actual melting point creation 165C. The second part of the experiment was the reaction of furan with maleic anhydride.This reaction produced 7-oxabicyclo2.2.1hept-5-ene-2,3-dicarboxylic anhydride. Maleic anhydride was combined with diethyl either to break the solid. Then furan was added and place under the hood for the next class period. During this time crystals were formed in the stopped flask. The melting point for the end product was observed at 113-114C. This indicated that the product was exo. The percent yield was calculated at 5.98%. There were many sources of error that could have contributed to the results of these experiments.The end product could have cooled a little longer to form more crystals. Also the crystals could have been dried more to produce erupt melting points. Separating the solvent from the test tube was not completely precise and mayhave alienated some of the product in the extraction. Scraping the crystals out of the flask or test tube was not easy and some of the product was lost during this step. Overall the experiment was a success.ReferenceWilliamson, K. Minard, R. Masters, K. Macroscale and Microscale Organic Experiments, 2011. Pg 617-629.

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