[Urbanium]

I have a compound I'm trying to isolate from the reaction mixture (DCM is the solvent) by precipitation with Et₂O, but it does not work, I get an oil which sticks to inner wall of the flask and NMR looks quite unclean. Funny thing is that when I monitor the kinetics, it seems the product forms, but the isolation is tricky.

Since the desired product is a salt, more precisely a triflate, I was wondering if adding some other salt with a bulky cation (tetrabutylammonium.. chloride, fluoride, hexafluorophosphate etc) instead of ether would cause the "ion exchange" and either the wanted compound with other anion or tetrabutylammonium triflate would precipitate.

Does anyone have experience with something similar? Triflates particularly?

[baum0372]

Does your salt have any long hydrophobic regions?  I worked with a salt of a molecule containing an octyl group (Br salt of a quaternary amine) and protocol said to precipitate into ether from DCM.  It formed a somewhat viscous residue, but upon vigorous stirring in ether for 4-8 hours, it became a manageable powder.  Not sure if this will work in your case but doing a salt exchange seems unnecessary at least to me.  Once you get a workable powder it may be easier to purify from there through trituration.