- Help Me With This Lab Pls Elaborate On The Meaning Of These Results Include Calculations 1 (10.05 KiB) Viewed 23 times
The essential reactants for dibenzalacetone synthesis are provided in Table 1. Table 1. Compound benzaldehyde acetone 95% ethanol 10% NaOH MW 106.04 58.08 46.07 Reactants used amount used 212 μL 74 µL 1.5 mL 2 mL mmol (calculate) (calculate) CAR 199 bp (°C) 178 130 56 MOOISSE 78 d (g/mL) 1.04 BORS 0.79 stutvrtine in 0.78 BHOOGE Experimental procedure: reaction setup To a 4 mL conical vial add 2mL of 10% of sodium hydroxide solution and a magnetic spin vane. Next, add 1.5 mL of 95% ethanol and stir it on a magnetic stirrer. After that, add 212 µL of benzaldehyde and keep stirring. The benzaldehyde initially insoluble will go into solution and a clear (pale yellow) solution is obtained. Next, add 74 µL of acetone and continue to stir. At some point, a yellow solid should form. Continue stirring the reaction mixture vigorously for another 20 min. At the end of that time, yellow, flaky crystals should be observed. After that time, cool the reaction mixture in an ice bath and isolate the product by vacuum filtration using Hirsch funnel Wash it 2 times with ice-cold water (using Pasteur pipette). Weigh and record the amount of you crude product.
Next, TA will prepare a water bath. You will prepare a separate tube, add-2 mL of ethanol to it and heat it in water bath. Transfer your product into large test tube. Using a minimal amount of hot ethanol (from your hot ethanol tube) dissolve your dibenzalacetone. You will want to keep your tube in a water bath while dissolving the product. After you obtain a translucent solution, remove your tube from the bath and let it cool down to room temperature. Once reached, place your tube into ice bath to further cool it down. Keep it on ice for 5 minutes and then filter it off using Hirsch funnel. Dry your product in the oven (TAs will set the oven temperature) and keep it for 10 min in there. Obtain mass of your recrystallized product and calculate the recrystallization yield. Product characterization Take your recrystallized product and record IR, 'H NMR and ¹3C NMR spectra. Record the m.p. of your product as well. The m.p. apparatus should be operated in a range of 80 -150 °C. Your TA will set it up for you.