Procedure: Week One Add 0.50 g of 4-bromobenzoic acid (2.5 mmol) and 0.37 g of phenylboronic acid (3.0 mmol) to a 125 mL Erlenmeyer flask containing a stirring bar. In a separate 50 mL beaker, add 0.80 g of sodium carbonate (7.5 mmol) and 15 mL of deionized water and stir until dissolved. Add the solution of sodium carbonate to the reaction flask containing the arylbromide and arylboronic acid and stir the resulting mixture vigorously until all the reactants are dissolved. The process of dissolution will take about 10 minutes. Meanwhile, measure 1.0 mL of the palladium catalyst solution using a measuring cylinder. The catalyst solution will already be prepared; the concentration of palladium in this stock solution is 0.25 mM. Once the reactants are dissolved, begin heating the solution (the final reaction temperature will be 70 °C) and add the palladium catalyst solution to the flask by pipette. Record any changes in the appearance of the reaction mixture throughout the procedure. The product of the reaction should precipitate as a white solid. The target temperature for this reaction is 70 °C so after 5 minutes of reaction time, measure the temperature of the reaction. To ensure the thermometer does not break, stop the stirring when monitoring the temperature of the reaction mixture. Allow the reaction to run for at least 30 minutes at 70 °C. After this time, turn off the heat and let the reaction cool to room temperature. Once the flask is at room temperature, place it in an ice bath. Position the flask and ice bath so that the mixture is still stirred efficiently. While the mixture is stirring, slowly pipette in 25 mL of 1M HCl directly into the flask. (Caution! The HCI must be added dropwise! The HCI reacts with the excess carbonate to generate carbon dioxide. If the HCl is added too quickly, the solution may foam over the reaction vessel.) The HCl solution quenches the excess carbonate and also converts the sodium carboxylate product to a carboxylic acid. Stir for 5 minutes once all of the HCl is added. Isolate the crude product by vacuum filtration and use about 5 mL of water to rinse the product out of the flask. Let the product dry on the filter for at least 2 minutes. Next, transfer the partially dried product to a 50 mL beaker and purify your product by recrystallization. First add 4 mL of 1M HCl and heat the stirred solution to about 70 °C. Slowly add enough ethanol to the solution so that all material dissolves (approximately 30 mL EtOH). Let the solution cool to room temperature and then place the beaker into an ice bath for 15 minutes to complete the recrystallization. Isolate the crystalline product by vacuum filtration. A few milliliters of cold ethanol can be used to wash product out of the beaker if

Procedure: Week One Add 0.50 g of 4-bromobenzoic acid (2.5 mmol) and 0.37 g of phenylboronic acid (3.0 mmol) to a 125 mL Erlenmeyer flask containing a stirring bar. In a separate 50 mL beaker, add 0.80 g of sodium carbonate (7.5 mmol) and 15 mL of deionized water and stir until dissolved. Add the solution of sodium carbonate to the reaction flask containing the arylbromide and arylboronic acid and stir the resulting mixture vigorously until all the reactants are dissolved. The process of dissolution will take about 10 minutes. Meanwhile, measure 1.0 mL of the palladium catalyst solution using a measuring cylinder. The catalyst solution will already be prepared; the concentration of palladium in this stock solution is 0.25 mM. Once the reactants are dissolved, begin heating the solution (the final reaction temperature will be 70 °C) and add the palladium catalyst solution to the flask by pipette. Record any changes in the appearance of the reaction mixture throughout the procedure. The product of the reaction should precipitate as a white solid. The target temperature for this reaction is 70 °C so after 5 minutes of reaction time, measure the temperature of the reaction. To ensure the thermometer does not break, stop the stirring when monitoring the temperature of the reaction mixture. Allow the reaction to run for at least 30 minutes at 70 °C. After this time, turn off the heat and let the reaction cool to room temperature. Once the flask is at room temperature, place it in an ice bath. Position the flask and ice bath so that the mixture is still stirred efficiently. While the mixture is stirring, slowly pipette in 25 mL of 1M HCl directly into the flask. (Caution! The HCI must be added dropwise! The HCI reacts with the excess carbonate to generate carbon dioxide. If the HCl is added too quickly, the solution may foam over the reaction vessel.) The HCl solution quenches the excess carbonate and also converts the sodium carboxylate product to a carboxylic acid. Stir for 5 minutes once all of the HCl is added. Isolate the crude product by vacuum filtration and use about 5 mL of water to rinse the product out of the flask. Let the product dry on the filter for at least 2 minutes. Next, transfer the partially dried product to a 50 mL beaker and purify your product by recrystallization. First add 4 mL of 1M HCl and heat the stirred solution to about 70 °C. Slowly add enough ethanol to the solution so that all material dissolves (approximately 30 mL EtOH). Let the solution cool to room temperature and then place the beaker into an ice bath for 15 minutes to complete the recrystallization. Isolate the crystalline product by vacuum filtration. A few milliliters of cold ethanol can be used to wash product out of the beaker if

Introduction to General, Organic and Biochemistry

11th Edition

ISBN:9781285869759

Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres

Publisher:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres

Chapter8: Acids And Bases

Section: Chapter Questions

Problem 8.64P

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