13C NMR 2 Chemical shift 2 Chemical shifts 2 Conformations 2 Density functional calculations 2 Density functional theory 2 Derivatives 2 Electrostatic response 2 Functional groups 2 Intramolecular interactions 2 Maleimide/phthalimide derivatives 2 Methoxy chemical shifts 2 Methoxy group 2 Methoxy group conformational effect 2 Methoxy groups 2 NMR 2 Phthalimide derivatives 2 Substituent chemical shifts 2 Substituted dimethoxyphenethylamines 2 Substitution reactions 2 article 2 calculation 2 carbon 2 chemical binding 2 chemical compound 2 chemical interaction 2 chemical structure 2 chlorine 2 electricity 2 electron 2