Lab 11

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Texas Tech University *

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3106

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Chemistry

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Feb 20, 2024

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[Last Name] 1 Ubani Ikonne My Phan Section 302 Lab Partners Jason Hamdan Christopher Marpa Date :11/13/22 Lab 11 Formation Of Bromohydrin:An Addition Reaction Purpose : To explore an electrophilic addition reaction involving bromine and water to an unsymmetrical Allene to give a bromohydrin Reaction And Physical Properties Table: Safety: N-bromosuccinimide Risk Statements: Causes serious eye/skin/respiratory irritation. Light/moisture sensitive. Safety Statements: Inhalation: Remove to fresh air; give artificial respiration. Ingestion: Rinse mouth with water. Skin/Eye Contact: Flush with water. 1-methylcyclohexene Risk Statements: Flammable liquid/vapor. Causes serious eye/skin/respiratory irritation. Safety Statements: Inhalation: Remove to fresh air; give artificial respiration. Ingestion: Rinse mouth with water. Skin/Eye Contact: Flush with water. Tetrahydrofuran

[Last Name] 2 Risk Statements: Highly flammable. Causes serious eye/skin/respiratory irritation. May form explosive peroxides. Safety Statements: Inhalation: Remove to fresh air; give artificial respiration. Ingestion: Rinse mouth with water. Skin/Eye Contact: Flush with wat Procedure In a 5 mL canonical vial with a spin vain pointed downward, add about 0.370 g of NBS. To the vial, add 1 mL of DI water, 1 mL of THF, and 240 μL of 1-methylcyclohexene (set to 120 μL on micropipette; this is to be done twice). Mix the resulting mixture for 10 minutes under the hood. Maximize the stirring rate on the stir plate; the vial can be clamped or put into a 50 mL beaker. Various reactions can be mixed on the same plate. Subsequent to waiting the 10 minutes, the solid should be completely gone and it should be colorless. Using a squirt bottle, add 2 mL of DI water. If the vial that is being used had graduations then it should be close to the 5 mL line. Mix for 2 minutes. In a 5 mL canonical vial with a spin vain pointed downward, add about 0.370 g of NBS. To the vial, add 1 mL of DI water, 1 mL of THF, and 240 μL of 1-methylcyclohexene (set to 120 μL on micropipette; this is to be done twice). Mix the resulting mixture for 10 minutes under the hood. Maximize the stirring rate on the stir plate; the vial can be clamped or put into a 50 mL beaker. Various reactions can be mixed on the same plate. Subsequent to waiting the 10 minutes, the solid should be completely gone and it should be colorless. Using a squirt bottle, add 2 mL of DI water. If the vial that is being used had graduations then it should be close to the 5 mL line. Mix for 2 minute No longer stir to allow the layers to separate. The organic layer is the bottom and the top layer is water. THF is less dense than water however, the bromine-containing product’s weight dissolved in the THF layer makes the organic layer heavier than the water. Cautiously pipet the organic layer and place it in a shell vial. If some water has moved into the pipet, allow the layers to separate then cautiously dispense the bottom layer into the vial. Dry the solution with a small portion of anhydrous magnesium sulfate. There will be clumping which is fine as it will be removed in the following step. Via silica gel, the succinimide by-product will be removed by filtering the product mixture. Place a small amount of cotton into the disposable pipet and fill it with silica gel halfway by dipping it repeatedly. Pre-weigh a clean vial and clamp the pipet under the tip. From the silica gel column, pipet the dry organic layer. To the vial, place 1 mL of CH2Cl2 along with the drying agent. To break up the drying agent, utilize the pipet tip or spatula. Pipet the solution to the column. Utilize the pipet bulb to move the solution through the silica gel by applying gentle force to the top of the pipet column. The steps that mention CH2Cl2should be repeated twice that way the drying agent is extracted with a total of 3 mL of CH2Cl2. This should be moved into the preweighed shell vial. Evaporate the solvent in the hood and gently heat with

[Last Name] 3 the hotplate set to 100-150°C and carefully blow air. The vial can be placed in a 50 mL beaker. When the level of the liquid no longer decreases and the lower part of the vial is warm, most of the THF and CH2Cl2should be gone. A clear liquid should be obtained. Weigh the vial with the isolated product. If the solvent has been completely evaporated, the weight should stay consistent Data and observations: Mass of empty vial 4.1796g Mass of vial with product 4.7036g Mass of product 0.524g Percent yield 134.015% An OH group is seen at 341.27 Csp3 bond can be seen at 2936.11

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[Last Name] 4 Molecular peak 193.9

[Last Name] 5 Peak # 7 Ret Time 4.394 Area 137325 Calculations Mass of Vial with product- mass of empty vial 4.70316g-4.1796-0.524 Theoretical 0.00024ml/0.811/96.17*193.082 =0.000039078g Percent yield 00.524/0.0039078*100=134.015% Conclusion discussion We were able to successfully use an electrophilic addition reaction for this lab to produce bromohydrophin. We also performed an Ir spectrum,gas chromatography and mass spec. AN oh group can be seen at 3417.27 and csp bond can be seen at 2936.11 in the gas chromatograph peak 7 contains a bromohydropin in the mass spec graph the molecular ion is identified to be 193.9 when calculating our percent yield we got an high percent yield this mens that either th solvent did not fully evaporate. It was probably due to our judgement that we stopped the evaporation process leading to some solvent remaining in the sample

[Last Name] 6 Post 1.

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[Last Name] 7 2. The peak at 330cm would mean the presence of OH group and because of this presence the peak would confirm the formation of a product. If the starting material were completely reacted then the peak for the alkene would be 1600-1700cm would be missing from the IR spectrum 3. The peak at 1700cm would indicate that the reaction is not fully complete