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Meeting 15 (Acetyl Ferrocene)
Important Announcements:
1. The proposal is due on November 14, 2008 at 5 pm in YH 3077 E (If you have problems please see me asap!). Late proposal will not be accepted and will lead to an automatic "F"-grade for the course. The important references have to be attached to the proposal. The proposal has to be submitted to turnitin.com as well (same course ID as before) by 11 pm on November 17, 2008, only one per group! Make sure that you have an electronic copy of your proposal with you.
2. The next quiz (=quiz 6) will be administered on November 13, 2008 at 11 am. It will cover the esterification and nitration reaction. Make sure that you show up on time. Otherwise you will not be allowed to take the quiz.
3. In the lab, you will only carry out the acylation of ferrocene, but not the synthesis of ferrocene. This part will be done individually and not in groups.
4. 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 and November 14, 2008 in your regular lab section. The postlab for Grignard project is due on November 18/19, 2008.
Homework assignments (due November 13/14, 2008)
1. Referring to the synthesis of acetyl ferrocene, answer the following questions.
a. How is the acylium ion generated in the lab? Show pertinent chemical equation(s). Which advantage does this method have?
b. The acylium ion is considered a weak electrophile compared to the nitronium ion. What are the impllications in terms of the reaction?
c. Why is it important to "neutralize" the organic layer before performing the column chromatography step? Which pH-value is the student looking for here?
d. A student redissolves the crude product in 20 mL of dichloromethane and transfers the solution onto the column? What will he observe?
e. During the flash chromatography step different solvents are used. Which ones are those and why are they used?
f. In which sequence do the compounds elute off the column?
g. The 1H-NMR spectrum of acetyl ferrocene exhibits three signals at from d = 4-5 ppm. Rationalize this observation.