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Meeting #12
General Announcements
1.
1. Make sure that you turn in a hardcopy of your research paper by Friday, November 6, 2009 at 5 pm and the electronic version to turnitin.com as well (CourseID: 2770101, Password: Chem30CL (no spaces!)). Late reports will be deducted points (10% per day including the weekend and independent why the report is late). If you do not submit the report online by Monday, November 9, 2009 at 10 pm, you will receive a "zero" score for the paper. In addition, it will be reported to the Dean of Students. Any plagiarism, partial or full resubmission of a papers or/and other forms of cheating will result in a report to the Dean of Students as well. Make sure that you cite your sources and try to use your own words as much as possible. Here is a checklist what should be included into the report. If you have any questions, please contact your TA or instructor asap, and not an hour before the submission deadline.
2. The next quiz (=quiz 5) will be administered on Thursday, November 5, 2009 at 11 am and will cover steps 3 of the Lidocaine project, MS, GC and NMR spectrocopy of epoxides. Make sure that you show up on time. Otherwise you will not be allowed to take the quiz.
3. Please look start looking for a partner for the last project. Your partner should be in a different time slot than yourself i.e. if you are in T/R morning section, your partner should be in section in the T/R afternoon section or in the W/F afternoon section.
4. If possible both reactions (esterification and nitration) should be carried out during meeting 12. This will give you more time to recrystallize the final product and get better quality crystals. The final product has to be turned in to the TA by November 6, 2009. Late submission will not receive any credit. Sorry! :-(
Homework questions
1. Referring to the Esterification carried out in the lab, answer the following questions. Show chemical equations and intermediates where appropriate.
a. Why is it imperative that the benzoic acid is as dry as possible for the reaction?
b. What is the function of methanol in this reaction?
c. After the reflux, the procedure asks to cool the reaction mixture first and then poured it into cold water. What is the purpose of this step?
d. Why are the combined the organic layers extracted with sodium bicarbonate? How does the student know that he is done with this step?
e. How does the final product look like?
2. Referring to the Nitration reaction carried out in the lab, answer the following questions. Show chemical equations where appropriate.
a. What is the electrophile in this reaction? How is it obtained in the lab?
b. Why is it important to dissolve the ester in concentrated sulfuric acid prior to introducing the electrophile? Show the appropriate intermediate.
c. The temperature has to be well controlled during the reaction. Why is this important and how is this accomplished?
d. The crude product is recrystallized. Which solvent is used? Rationalize the choice.
e. What are the major changes in the IR spectrum going from methyl benzoate to the product of the nitration reaction?