GreenD - 8-4-2012 at 07:41
Hi,
I've got a paper that details the formation of an amide from the corresponding aldehyde.
My amide is from the respective aldehyde of CAS: 1205-17-0
The literature extracts the amide from a solution of ammonium hydroxide and THF, using DCM.
At the present moment, as this solution can be dangerous (if you find the paper you will giggle at a possible side-product), I need to extract the
amide, but I only have turpentine and naptha.
I think the polarity of the amide is too great to be extracted by either. I would attempt both but I'd rather save my precious than destroy it or make
a nasty mess. Is there another substitute for such an amide in such a solution? Perhaps ethyl acetate?
DDTea - 8-4-2012 at 12:25
oh dear. I did giggle.
Short version: Ethyl acetate sounds like a reasonable solvent because it has a dipole moment that can interact with the quadrupole in your amide.
Boring stuff:
Selecting solvents involves exploiting the chemical properties of both solvent and solute to find favorable, stabilizing interactions. Basically,
the solute has to feel it's energetically desirable to hang out with solvent molecules. Terms like "more polar" and "less polar" are gross
simplifications that can send the hapless chemist in a lot of bad directions.
Important physical properties in solvent selection are hydrogen bonding, dipole moments, and London dispersion forces (very important in molecules
with heavy atoms like Cl, Br, S, etc). A much better explanation of this, complete with helpful tables and diagrams, is given in Ch. 6 (IIRC) of
Snyder and Kirkland's "Introduction to Modern Liquid Chromatography" (2nd ed).