IMPORTANT NOTES Experiment 5: Electrophilic Aromatic Substitution -- CER REAC 716 Each student carries out one of two possible reactions in Experiment 5. You will be told at the beginning of the lab section which of the reactions you are supposed to carry out. Hence, you need to prepare for both reactions. 1. Run this reaction with TWICE the scale given in the procedure, that is, double the amount of reagents throughout the experiment. Since we are doubling the amount of reagents, answer pre-lab question #3 according to the amounts you will be using. 2. Perform a TLC analysis of your crude and recrystrallized products. a. Save a small sample (about 20 mg) of your crude product (before recrystallization), just enough for a TLC solution. Place in a small test tube and dissolve in 1 ml methanol. b. Set up a TLC developing chamber as described in experiment #4. c. Use the following solvent systems: * 40 % ethyl acetate in hexane for the acetanilide reaction (4 ml ethyl acetate and 6 ml hexane). * 15 % ethyl acetate in hexane for the methyl benzoate reaction (1.5 ml ethyl acetate and 8.5 ml hexane). d. Standard solutions of possible products will be available for comparison of Rf's values. Your products are only visible under ultraviolet light, so use an UV lamp to see them. Mark each one. Standard for acetanilide reaction para-nitroacetanilide Standards for methyl benzoate reaction 3-nitro-benzoic acid 3-nitro methyl benzoate 3,5-dinitro methyl benzoate e. Provide a picture of your TLC plates in your report with each spot identified and the solvent system you used. Include the following Table in your lab book. This is the "table" referred to in the file "grading scheme". Electrophilic Aromatic Substitution Name of aromatic reactant _______________ Amount of aromatic reactant used, _______________ g _______________ moles Product obtained _______________ g _______________ moles Product theoretical yield _______________ g _______________ moles Product yield _______________ % Product Characterization: Melting Point: ______________ oC TLC analysis: 1. Picture of TLC plate with spots identified 2. Solvent system used Product identification (specify regiochemistry) _________________