Dear AMMRL members:
Has anyone done work to salt forms of a basic drug using proton NMR. I know
that the spectrum of the base versus the HCl is quite different in
chloroform-d. But what about distinguishing HCl from HBr from HI, etc.?
A chemist in this lab just made these salt forms of a basic drug and I have
just run proton NMR of them in chloroform. I was always under the impression
that the electronegativity would be the dominant factor in where the chemical
shifts would be; hydrochloride salt would be higher than the HBr which would be
higher than the HI. However, experimentally this is not the case. The
chemical shifts are all very close with the HCl chemical shifts being slightly less
than those of the HBr and HI. How come?
Are there other solvents or techniques I can use that do a better job of
discerning salt forms?
I look forward to your responses.
Patrick Hays
Received on Tue Mar 23 2004 - 17:38:50 MST