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    There is a mixture of an aldol product, dissolved in ethanol and water with NaOH, we are asked to design a work up, could I isolate the product just by dissolving in DCM, then washing the aqueous layers with more DCM, and playing on a rotary evaporator?
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    (Original post by jacksonmeg)
    There is a mixture of an aldol product, dissolved in ethanol and water with NaOH, we are asked to design a work up, could I isolate the product just by dissolving in DCM, then washing the aqueous layers with more DCM, and playing on a rotary evaporator?
    Could do but it depends on the amount of ethanol you've got there and the solubility of the particular aldol product in that as to how effective your DCM extraction is. Also depends on whether you want a lab work up or manufacturing scale one. If the latter then definitely would not be using DCM as extraction solvent if at all avoidable.
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    (Original post by TeachChemistry)
    Could do but it depends on the amount of ethanol you've got there and the solubility of the particular aldol product in that as to how effective your DCM extraction is. Also depends on whether you want a lab work up or manufacturing scale one. If the latter then definitely would not be using DCM as extraction solvent if at all avoidable.
    It's small scale, theoretical yield of 5 mmol of product, in 15ml of ethanol and similar amount of sodium hydroxide solution, i'm not sure about the solubility, would it make a difference how much DCM I used? Apart from taking longer to evaporate it, not sure how many times I'd need to wash the aqueous layer. Some product came out after leaving to stir for a few days, a very viscous and extremely sticky oil, but there's still some left in the solution, I used cyclopentanone and 2-methylbenzaldehyde
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    (Original post by jacksonmeg)
    It's small scale, theoretical yield of 5 mmol of product, in 15ml of ethanol and similar amount of sodium hydroxide solution, i'm not sure about the solubility, would it make a difference how much DCM I used? Apart from taking longer to evaporate it, not sure how many times I'd need to wash the aqueous layer. Some product came out after leaving to stir for a few days, a very viscous and extremely sticky oil, but there's still some left in the solution, I used cyclopentanone and 2-methylbenzaldehyde
    Those starting materials suggest a very lipophilic product to me so you could perhaps extract with toluene. Back wash with brine, dry over MgSO4 and then evaporate solvent
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    http://www.chemspider.com/Chemical-S...53a&page_num=1

    Look at this.
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    (Original post by TeachChemistry)
    Those starting materials suggest a very lipophilic product to me so you could perhaps extract with toluene. Back wash with brine, dry over MgSO4 and then evaporate solvent
    Hey thanks for the response, what would the brine do exactly?
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    I used 1:1 ratio of the aldehyde and ketone so I don't think ill get that
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    (Original post by jacksonmeg)
    I used 1:1 ratio of the aldehyde and ketone so I don't think ill get that
    If you used 1:1 then you will get a mixture I expect.

    Saturated brine removes water and maybe some ethanol.
 
 
 
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