LAB REPORT! EXPERIMENT#5‚6! MANPREET KAUR KHAIRA! LAB PARTNER: VIAN RAIES! The purpose of this lab exercise was to perform the bromination of (E)-1‚2-diphenylethene (trans-stilbene) by addition reaction in which bromine was added across the double bond to yield a vicinal dibromide. The next step was to perform a double elimination reaction by product gained to synthesize an alkyne‚ that is‚ 1‚2-diphenylacetylene. The two major techniques used in this lab were TLC analysis and UV-vis spectroscopy
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Bromination of trans- Stilbene to form 1‚2- Dibromo- 1‚2-diphenylethane Abstract 1‚2-dibromo-1‚2-diphenylethane was produced by the bromination of trans-stilbene through the addition of hydrobromic acid (HBr) and hydrogen peroxide (H2O2). This experiment was a greener bromination of stilbene because bromine was generated in situ and ethanol was used as the solvent. The melting point (243.30°C)‚ mass (.427g)‚ and percent yield (45.54) of the crystals were recorded. The FTIR
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only the trans product; it uses a much milder base that is easier to handle; and it gives a water soluble byproduct which is easy to separate from the product. The reason that these advantages occur is a change in the structure of the ylide. Instead of a tripheylphosphine ylide‚ we use a diethylphosphonate ylide. The protons are much more acidic and its byproduct is negatively charged. The reason why we chose to create trans-stilbene is become of its many practical applications. Stilbene exists
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Abstract The bromination of trans-cinnamic acid was completed to determine dibromide’s stereochemical structure and its mechanism. After the addition of bromine to trans-cinnamic acid‚ the product was identified by its melting point and infrared spectrum resulting in erythro-2‚3-Dibromo-3-phenylpropanoic acid after comparing similar properties. Introduction In this lab‚ the bromination of trans-cinnamic acid was completed to determine dibromide’s stereochemical structure‚ and from there determine
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Greener Brominations Abstract In this experiment‚ trans-stilbene was brominated and debrominated with the use of three methods: bromination with pyridinium tribromide‚ bromination with hydrogen peroxide and hydrobromic acid‚ and debromination with zinc. The yields of parts A‚ B‚ and C are as follows: 68.6 %‚ 54.6 %‚ and 55.9 %. Introduction In the chemical process of bromination‚ an alkene is halogenated with bromine. Solvents that are typically used include methylene chloride and carbon
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Alkene addition: Bromination of (E) Stilbene Introduction: In this lab we used the greener approach‚ which involves the addition of bromine across a double bond. When bromine reacts with E-stilbene (trans-1‚2-diphenylethene)‚ two new chiral carbons are created from the sp2 carbons‚ therefore 3 different dibrominated stereoisomers are possible: meso-(1R‚2S)‚ or the raceminc mixture-(1R‚2R) or (1S‚2S)-dibromo-1‚2-diphenylethane (Gilbert‚ 2010). When the bromination ion intermediate proceeds
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successfully produce stilbene dibromide by using a more sustainable approach‚ which would prevent less environmental issues. This was done by brominating trans-stilbene and then using the elimination process on the dibrominated product. This process is considered “greener” compared to the original bromination procedures. In order to create the alkyl halides‚ which are able to undergo chemical transformations more readily than the carbon-carbon double bond‚ onto the trans-stilbene the addition process
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Bromination of Acetanilide Objective: The objective of this experiment was to use melting point and NMR to determine which of two isomers‚ ortho or para‚ would most likely form after brominating Acetanilide through electrophilic aromatic substitution. Procedure/Observations: 1. Weigh out ~280 mg of acetanilide in a 10 mL r.b. flask with a stir bar. 2. Then‚ add 2.0 mL of glacial acetic acid using a calibrated Pasteur pipet. 3. Stir the mixture until all of the acetanilide has dissolved
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Bromination Solo Experiment 3 – Individual Lab Report (Save as pdf and submit‚ due by 12:00 NOON one week after experiment) Last Name: First Name: TA Name: Date Lab Performed: Date Lab Submitted: Group A‚ B‚ or C: Comments for Grading TA: (Please indicate if you performed the lab on a day other than your regularly scheduled day and/or with a TA other than your regular TA). Page Limit: report must not exceed FIVE pages (including this page) LIMIT DOES NOT INCLUDE ANY GRAPHS‚ SPECTRA
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Bromination of Acetanilide Introduction: Bromination of acetanilide to 4-bromoaniline was studied in this experiment. One of the most important mechanism with the reaction of aromatic compounds is the electrophilic aromatic substitution reactions(wade‚2013). The electrophilic aromatic substitution enable scientists to make substituted aromatic compounds. However‚ substitution groups affect the electrophilic substitution mechanism. A nitrogen atom attached to hydrogen is learned to be a powerful
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