I've currently synthesized several imines from aldehydes and amines. However, I am trying to get rid of any residual aldehyde and amine peaks to obtain an isolated yield without much luck. Thus far I've tried charging my alumina column with MeOH, then with triethylamine, then washed twice with methanol and thereafter flushed with hexane before loading of my sample. I've recently even bought a new batch of neutral alumina and TEA. Any ideas will be greatly appreciated.
I'm sorry, there isn't enough information to properly give advice. What is the problem? The compound won't elute, or it decomposes?
What solvents dissolves your sample? What other functional groups are on the molecule? This information gives a sense of the polarity of your compound, and what solvents should elute it.
If it won't elute, you may need a stronger solvent, such as water. You may need to adjust the pH as well. The technique is called "HILIC"- hydrophilic interaction liquid chromatography, and it works well on alumina. The technique starts with an organic solvent, usually with a little water, and a gradient to higher water concentrations.
Here's are some HILIC app notes (although diol and amine are mentioned, it works with alumina and silica too): http://www.teledyneisco.com/liquidChromatography/Chromatography%20Documents/Application%20Notes/HILIC%20Purification%20Strategies%20App%20Note.pdf#search=hilic
http://www.teledyneisco.com/liquidChromatography/Chromatography%20Documents/Application%20Notes/RediSep%20Rf%20Gold%20Silica%20and%20Highly%20Polar%20Solvents%20App%20Note.pdf#search=hilic
If the compound decomposes, you may need a bonded phase such as C18, diol, or cyano. Although this describes purification of an epoxide, the same information holds for other delicate compounds- see: http://www.teledyneisco.com/liquidChromatography/Chromatography%20Documents/Application%20Notes/Purification%20of%20Delicate%20Compounds%20with%20RediSep%20Rf%20Gold%20Diol%20and%20Cyano%20Columns%20App%20Note.pdf#search=delicate
Please try with Basic alumina, It will help you to separate your product.
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