I would like to know if there is any especially while purifying a molecule and also in obtaining NMR spectrum of thus purified molecule. Does the presence of trace DEA or its impurities while recording NMR bring any additional peaks?
You first should ensure your compound will not react with DEA and is generally base stable. If your compound has any electrophilic sites this might be an issue.
Adding base to your column solvent can really help when purifying amines. If you are not able to remove all the DEA after the column, there will be extra peaks in the NMR spectra (from the ethyl chains). It's boiling point is 55C, so it shouldn't be too hard to get rid of, with plenty of co-evaporations with a polar solvent (e.g. methanol).
Personally I usually use a small amount of methanolic ammonia (10% NH4OH in methanol) for columning basic amines. Something like between 1-10% methanolic ammonia in DCM.
You first should ensure your compound will not react with DEA and is generally base stable. If your compound has any electrophilic sites this might be an issue.
Adding base to your column solvent can really help when purifying amines. If you are not able to remove all the DEA after the column, there will be extra peaks in the NMR spectra (from the ethyl chains). It's boiling point is 55C, so it shouldn't be too hard to get rid of, with plenty of co-evaporations with a polar solvent (e.g. methanol).
Personally I usually use a small amount of methanolic ammonia (10% NH4OH in methanol) for columning basic amines. Something like between 1-10% methanolic ammonia in DCM.
@Tom S Carter Thank you for the answer. I would surely give a try with methanolic ammonia and share my experience of amine purification. If my compound of interest has electrophilic sites and it is purified with the help of 0.5% v/v DEA, what could go wrong/change with the nature/property of this compound? And how it would affect the NMR spectrum?
@G. Balaji
If your compound has reactive nucleophilic sites, you could see reaction with the amine of DEA. But this would require a good leaving group. It would cause changes in the nmr signals near those of the reactive site, and new peaks for the ethyl chains of the incorporated DEA.
I'm guessing you are working on some kind of natural product? This is not likely to be a problem , unless it's some kind of delicate transient intermediate, normal amides/esters aren't going to be reactive enough.
- Badges
- Science topic