Problems Set (Meeting 10)

General Announcements

1. Make sure that you turn in a hardcopy of your research paper by Friday, February 12, 2010 at 4:30 pm and the electronic version to turnitin.com as well (CourseID: 3000041, Password: Chem30CL for Winter 2010 (no spaces!)). Late reports will be deducted points (10% per day including the weekend). If you do not submit the report online by Monday, February 15, 2010 at 10 pm, you will receive a "zero" score for the paper. In addition, it will be reported to the Dean of Students for attempted cheating. 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 use your own words. 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. The final version has to be submitted in a small binder! Loose paper collections, large binders or folders will not be accepted!!!

2. The next quiz (=quiz 4) will be administered on Monday, February 8, 2010 at 11 am. It will cover the entire Lidocaine project. Make sure that you show up on time. Otherwise you will not be allowed to take the quiz. No exceptions!!!!

3. The postlab report for the lidocaine project has to be written in the lab notebook and submitted to the teaching assistant. The due dates are February 16, 2010 and February 17, 2010 in your regular lab section. The report is worth 15 points.

4. The final product of the lidocaine project has to be turned in to the TA by February 10, 2010 at 4 pm for evaluation by the instructor. Late submission will not receive any credit. Make sure that you label the vial properly.

5. The instructor will provide an in-lab demonstration of the Grignard setup on Wednesday, February 10, 2010 at 4 pm in YH6086.

Questions

1. Referring to the conversion of a-chloro-2,6-dimethylacetanilide to lidocaine (step 3), answer the following questions. Show pertinent chemical equations.

a. Why is it important that the anilide is very dry here?

b. How many equivalents of diethylamine are needed for the reaction? How many are really used? Explain.

c. Why is it important that the reaction mixture is refluxed here?

d. During the work-up, the reaction mixture is first extracted with water. Which purpose does this extraction serve?

e. Afterwards, the organic layer is extracted with 3 M hydrochloric acid. Which layer contains the product after the extraction? In which form?

f. How is the product recovered after the previous step? How does the product appear at this point?

g. How could the purity of the lidocaine best be assessed?