Problems Set (Meeting 9)

Announcements

1. The next quiz will be administered on October 30, 2006 at 12 am and will cover step 1 of the Lidocaine project, NMR and GC/MS.

2. The final paper will be due on Thursday November 9, 2006 at 5 pm in YH3077E.

3. You should finish the first two steps on the first day of the project.

Questions:

1. Referring to the conversion of 2,6-dimethylnitrobenzene to 2,6-dimethylaniline (step 1), answer the following questions. Show pertinent chemical equations where appropriate.

a. Three equivalents of tin(II)chloride are used in the reaction. Explain briefly. How is this reaction carried out in industry?

b. Another important point is that the reaction has to carried out in a strongly acidic medium. Why is this necessary and how is this accomplished?

c. A salt is isolated from the first part of the reaction. A student decides to wash the salt with water. What would he observe?

d. Why is potassium carbonate used in the work-up?

e. Sketch the distillation setup. Which pieces are needed here?

f. How many signals are observed in the ¹H-NMR and the ¹³C-NMR spectrum for the compound?

2. Referring to the conversion of 2,6-dimethylaniline to a-Chloro-2,6-dimethylacetanilide (step 2), answer the following questions. Show a pertinent chemical equations where appropriate.

a. Acyl chlorides react easily with water. Which implications does this have for their use?

b. What is used as the solvent in this reaction? Rationalize this choice.

c. Why is sodium acetate solution added to the reaction mixture?

d. What is the melting point for the product?