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2-FA Infrared Spectrums

telling purity from a IR-Spectogram is not really possible maybe you could see 10% impurity but its defo the wrong analytical method, you better need a NMR, HPLC or GC spectra
 
Okay, thanks. Is it even though possible to say which one looks better? I've heard there is a difference between the white and yellow batch.
 
well the white spectra looks better because the signals are sharper but it looks more like the 2nd one was measured a bit to often
 
What's with the strong peak at 1740 cm-1? There should not be any C=O stretches present, if there are something has gone very wrong with the synthesis.

Also no primary amine peak at 3450 cm-1, erm. I guess it's the ammonium ion (why do this solid phase?), with further evidence for that with the broad peak at 1950 cm-1... Possibly at 1580 cm-1 you have an N-H bend. The huge, sharp peak at 770-735 cm-1 is also indicative of ortho-substitution, but the presence of the C=O stretch is kind of alarming and indicates that the reaction is really poorly cleaned up.

In summary, I think they're both pretty gross looking, China is still terrible at manufacturing even simple drugs, and the first one has a little less of the carbonyl impurity present.
 
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^ Good catch. The C=O stretch is a bit too far upfield to fit with common ketone solvents such as acetone or MIBK. It could be unreacted 2-fluorophenylacetone, but I would expect a slightly lower wavenumber. It's a perfect match for ethyl acetate or another aliphatic ester. There's also a strong signal which could be an ester C-O stretch at 1230 cm-1.

My guess would be that the product contains quite a lot of ethylacetate or a similar solvent, presumably from the recrystallisation. What does it smell like? Fruity?
 
Yeah, the shift to higher energy for the C=O stretch bothered me too, 1-Phenyl-2-propanone has a C=O stretch at 1725 cm-1. 2-Fluorobenzaldehyde has a peak around 1705 cm^-1, so it's not from that either I would guess. Definitely not the acetate salt because of the carbonyl peak shift. Ethylacetate would be the most obvious answer, and there's a lot going on around 1300-1100 cm-1 that could indicate that too.
 
Thank you guys. I hope i will find a better vendor with a better synthesized product. :|
 
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