[BARAJAN]

hi
I have a compound which shows a one spot tlc but the appearance is greasy despite it should be a white powder,so I decided to pass it through a column chromatography, although I have used a nonpolar combination(1:10-ethylacetate:n-hexane) the compound appearance has not changed, so what should I do?

[fledarmus]

It's possible that you have a small amount of grease or oil in your sample. For compounds that are mostly insoluble in hexane, I have had some success triturating the gooey sample with a small amount of hexane (add hexane and grind with a rounded glass rod until you get solid). Sometimes two or three triturations with fresh solvent are required.

[OC pro]

Do you have recorded NMR yet?

[BARAJAN]

Do you have recorded NMR yet?

no, I haven't, I'm trying to pure product before NMR

[BARAJAN]

For compounds that are mostly insoluble in hexane, I have had some success triturating the gooey sample with a small amount of hexane (add hexane and grind with a rounded glass rod until you get solid). Sometimes two or three triturations with fresh solvent are required.

thank you for your help, just a question, I can't understand why hexane can give solid  when the compound (probably impurities too) is insoluble in hexane 

[discodermolide]

If it is grease or oil it will dissolve in the hexane. Further triturating as describers will eventually form small nucleation centers which will start the crystallisation process.

[Raphael]

Run an NMR and try to make sure you have the right thing before you go crazy trying to purify it. If it's really dirty it might not help but it could give you an idea.

[Dan]

Run an NMR and try to make sure you have the right thing before you go crazy trying to purify it. If it's really dirty it might not help but it could give you an idea.

I agree with this.

Assuming it is the right compound, establishing what the impurity is will allow you to choose an appropriate purification procedure, at the moment it's guesswork.