[alexjaco]

Hello,

I am having a hard time purifying Boc-amines I have made by "standard" group chromatography.   Typically we use silica and a mixture of hexanes and ethyl acetate.  I have switched to basic alumina but still seem to get streaks and recover little product.  Anyone have ideas of a better solvent systems or techniques?

Thanks in advance!

[alphahydroxy]

You could try adding something like 1% of 10% methanolic ammonia to your eluant mixture (and it may be useful to change the amounts of ethyl acetate and hexane to keep the polarity of the whole the same.

For example, you could try 15ml ethyl acetate, 84 ml hexanes and 1 ml 10% methanolic ammonia to give 100 ml of eluant in total.

If you're out of methanloic ammonia, you could try a few drops of an aqueous solution, or few drops of triethylamine - just test each system out on TLC and use whatever works best for you.