Work-up? What's going on?

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Ponyshine
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Work-up? What's going on?

Post by Ponyshine »

Hello :)

The reaction below is a Lewis Acid (CuSO4) catalysed reaction of cyclopentadiene with glyoxylic acid in water (see link):

http://i63.tinypic.com/j9aadl.png

The work-up then involved extracting the excess cyclopentadiene in cyclohexane and collecting the product in the aqueous water layer. The aq layer was then saturated with NaCl. The product was then extracted into an organic ethyl acetate solvent layer.

My question is, what exactly is going on during the work-up? Why does the product dissolve in water initially before adding NaCl? And what exactly is happening when the aq layer is saturated with NaCl to make the product soluble in an organic solvent after this saturation? What is the role of the NaCl here to cause the product to go from dissolving in the aq layer to dissolving in the organic layer? Is it affecting the Lewis acid in some way?

Thanks very much!
:)
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ChenBeier
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Post by ChenBeier »

An organic compounds solubility in water will be disturbed by inorganic ions. In your case the the sodium chloride dissolves very good and push out the organic compound of the water and make it more easy to get it dissolved in an organic solvent.
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