Bromination of trans-cinnamic acid Essay

AbstractThe bromination of trans-cinnamic superman was completed to determine dibromides stereochemical structure and its mechanism. After the concomitant of atomic number 35 to trans-cinnamic hotulent, the growth was identified by its melting point and infrared spectrum resulting in erythro-2,3-Dibromo-3-phenylpropanoic panelling after comparing similar properties. IntroductionIn this lab, the bromination of trans-cinnamic point was completed to determine dibromides stereochemical structure, and from there determine whether the reaction is carried out(a) by the usual bromonium ion mechanism or a different mechanism. This is main(prenominal) in the determination of dibromides stereochemical structure, as a mechanism do-nothing be affected by changing a reactants structure.Cinnamic acid was used in this lab because as a naturally occurring compound, it has umpteen different uses. It is used as a flavoring, in perfumes, and is a reference to a large number of other natura l substances. Cinnamic acid is laborsaving in providing flowers with their bright colors, butterflies with their colorful wings, and gives fall leaves their evidenceable color. These examples reveal the day-by-day uses of cinnamic acid, and shows that the addition of bromide to this particular acid is nothing extremely complicated or an uncommon chemical compound, it is easily obtainable.After the addition of bromine to trans-cinnamic acid, the product is identified by its melting point and infrared spectrum. The product could be erythro-dibromo, threo-dibromo, or a combination of twain. Although obtaining a product consisting of both erythro and threo is possible, it results in an impure substance with a broad melting point range that contrasts pure dibromide. These particular compounds of erythro and threo are named as such to distinguish their two chiral centers, but no plane of symmetry. Both of these compounds are derived from wide sugars, erythrose and threose (Figure 1) .Figure 1. Structures of Erythro and Threo Products Compared to Erythrose and ThreoseAfter completing the addition of bromine ion acetic acid to a upshot of trans-cinnamic acid in the same solvent, the product that is obtained preserve be identified by comparing the properties of erythro-2,3-Dibromo-3-phenylpropanoic acid and threo-2,3-Dibromo-3-phenylpropanoic acid.Results and Discussion liquescent PointThe melting point was determined to be 202C, which is extremely culture to the literature value of erythro-2,3-Dibromo-3-phenylpropanoic acid, 204C. This is the first indicator that the product obtained possess a stereochemical structure resembling erythro-2,3-Dibromo-3-phenylpropanoic acid. Infrared SpectrumThe Infrared Spectrums quiet from the starting actual and the product look almost identical, with functional groups C=O(1700 cm-1), O-H(3300-2600 cm-1), and C=C (1680-1640 cm-1) present. MechanismsAlthough a variety of mechanisms can be suggested for the addition of bromine to an alkene, the addition of bromine to the C = C in our final product illustrates an anti-addition.data-basedThe reaction was done in the fume hood with proper preventative gloves on throughout the entire experiment. 10.0 mmol of trans-cinnamic acid was combined with 6.0 mL of frosty acetic acid with a stirbar in a 50 mL round-bottom flask. The round-bottom flask was placed on a charismatic stirrer with a separatory displace over the flask with the stopcock closed. 8.2 Ml of 1.25 M solution of bromine in acetic acid was poured into the separatory funnel and stoppered immediately. After starting the stirrer, the bromine/acetic acid solution was added in 5 portions once the color had faded to a aerial orange, about every 6 minutes, totaling 30 minutes for this process. Once the hold out addition of the bromine solution was added, the reaction stirred at 50C for 15 minutes. At the end of the 15 minutes,cyclohexenes were added drop wise while the stirring continued until the so lution was colorless. To separate, the mixture was cooled in drinking glass water until crystallization was observed. Through vacuum filtration, the solid product was collected and rinsed with portions of ice cold water until the odor derived from the acetic acid had disappeared. The 2.3-dibromo-3-phenylpropanoic acid was dried in order to measure its melting point.References1 examine is a modified version of an experiment found in Lehman, J.W. usable Organic Chemistry a problem-solving approach to the laboratory course, 3rd ed., Prentice-Hall, speed Saddle River, New Jersey, 1999. 2 www.sigmaaldrich.com3. www.chemicalbook.com