Problems Set (Meeting 10)

General Announcements

1. Make sure that you turn in a hardcopy of your research paper by November 9, 2007 at 5 pm and the electronic version to turnitin.com as well (CourseID: 1920120, Passwd: Chem30 CL for Fall 2007). Late reports will be deducted points (10% per day including the weekend). If you do not submit the report online by Monday November 12, 2007 at 11 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 4) will be administered on October 31, 2007 at 10 am and will cover most likely the entire Lidocaine project. Make sure that you show up on time. Otherwise you will not be allowed to take the quiz.

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 November 13/14, 2007 in your section.

4. The final product has to be turned in to the TA by November 2, 2007 at 5 pm for evaluation by the instructor. Late submission will not receive any credit. Make sure that you label the vial properly.

Questions

1. Referring to the conversion of a-chloro-2,6-dimethylacetanilide to licocaine, answer the following questions. Show pertinent chemical equations.

a. Why is it important that the a-chloro-2,6-dimethylacetanilide is as dry as possible for this reaction?

b. The procedure asks for three equivalents of diethylamine. What does mean? Why is this necessary?

c. How does the student know that the reaction is proceeding?

d. During the work-up, the reaction mixture is extracted with water and hydrochloric acid. Which purpose do these two extractions serve? In which layer is the product after these two extractions?

e. At some point in the work-up, concentrated potassium hydroxide solution is added. Explain why and show the pertinent equation.

f. Why is the product redissolved in hexane after being isolated in e.?

2. Amides

a. Why does the ¹H-NMR spectrum of many amides change as the temperature of the solution changes?

b. Usually primary amides have higher boiling points than secondary or tertiary amides. Rationalize this observation.

c. The reaction of diacids with diamines often leads to polymeric amides. Give an example and explain what this polmer is used for?