Experiment 5: Reductive Amination (Pt. 2)

Prelab and Procedure Questions

Ethanol - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Proton

LiAlH4 - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Hydride

Acetic acid - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Proton

Methyl acetate - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Proton

Benzene - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Hydrogen

Pyridinium - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Proton

Wilkinson's catalyst - Is the highlighted atom best described as a hydrogen, proton, or hydride?

Hydride

Predict the product of the reaction below:

B

What is the purpose of saving some imine for TLC analysis? Select all that apply.

To determine reaction progress and to compare Rf’s of the starting material and product

What is this gas likely to be?

Hydrogen gas

What is the aqueous layer?

\n Water and byproducts from NaBH4

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What is the consequence if this step is omitted?

\n There will be more water in the organic layer and will require more sodium sulfate for drying

What is the problem with having some ethyl acetate in the IR spectrum?

The signals from residual aldehyde starting material may be blocked

A TLC analysis using 10% EtOAc in hexanes indicated an Rf = 0.05 for the product. What should you do from here?

\
* Repeat the TLC analysis using a solvent mixture with greater polarity (50% EtOAc in hexanes) to increase the Rf  to 0.3.