Last updated Tue, Oct 8, 2002

1. General

Review: Chromatography, 13C-NMR spectroscopy, HETCOR, DEPT spectroscopy, TLC technique

Make sure that you are enrolled in the course by now.

2. Experiment

You will have to work on three experiments during the first lab period: resolution of the amine, formation of the alcohol and the synthesis of Ce(OH)3(OOH). The best strategy would be to start the resolution first and work on the synthesis of the Ce(OH)3(OOH) while the salt is crystallizing. The alcohol synthesis should be started last and placed in the neighboring lab.

a. Resolution of the amine

The desired product crystallizes together with some trapped material. It is important that the tartaric acid is added slowly. This is a neutralization reaction and the mixture can splash out. The crude product has to be recrystallize from hot water (~1 g/10 mL water). It should be white after the recrystallization.

b. Synthesis of Ce(OH)3(OOH)

It is very important to add the 30% hydrogen peroxide slowly otherwise the mixture will foam heavily. Concentrated hydrogen peroxide is unstable and can decompose rapidly when in contact with transition metals and/or bases. Careful! The filtered product needs to be washed thoroughly with water and then acetone in order to remove the majority of the water. A dry product leads to better results in the oxidation.

c. Synthesis of the alcohol

The reaction of the phenol involves the use of formaldehyde solution. Formaldehyde is a carcinogen and should be handled appropriately. The sodium hydroxide has to dissolve completely first before the formaldehyde solution is added.

The purity of final product has to be checked by TLC. In many cases, it will still contain significant amounts of unreacted phenol. If this is the case, the student will have to recrystallize the crude product from hexane.

3. Things to think about

a. How can you isolate the (S, S)-form of the amine?

b. By looking at the polarity of the alcohol and the phenol, which compound is stronger absorbed on the sililca?

c. Why is Ce(OH)3(OOH) used for oxidation instead of 30% H2O2?