i have some new derivatives of compounds which i have synthesis, in this substituents such as furan,followed by ph, and p-MeO appears higher chemical shift as compare to PNO2, P-cl,3-cl,3-br,4-br substituents, as i have study so far substituents which have electron withdrawing group has more higher chemical shift but instead of this furan substituents proton peak shift more higher, is it furan are consider to be EWG but what about PH, P-MeO which is EDG? any idea
Chemical shifts depend always from a combination of inductive and resonance effects, without knowing the exact structures its impossible to comment.
actually i want to know the derivatives of quinazoline like furan,followed by Ph,PMeOPh substituted are showing higher chemical shift(more downfield) in NMR spectrum than P-NO2Ph derivatives of quinazoline Jukka Salminen
actually i want to know the derivatives of quinazoline like furan,followed by Ph,PMeOPh substituted are showing higher chemical shift(more downfield) in NMR spectrum than P-NO2Ph derivatives of quinazoline Jukka Salminen
Resonance effects, deshielding from aromatic/non-aromatic ring systems, intramolecular hydrogen bonding, rigid structure...?
well thank you Jukka Salminen the substituent of quinazoline such as furan shows higher deshielded chemical shift in C-4 hydrogen as compare to other (which follow as ph and P-meo and P-No2). did you mean its because of resonance effect?
The question is too broad to discuss like this. If you have some NMR-spectroscopist near show your compound structure together with the spectrum and ask for an opinion. I have no longer access to the litterature needed to contribute.
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