Structural Factors Affecting the Basicity of ω-Pyridylalkanols, ω-Pyridylalkanamides and ω-Pyridylalkylamines

Article abstract of DOI:10.1002/hlca.19820650621

The present paper describes the preparation by conventional methods (when not available commercially) and the pK_a-determination of the α-, β- and γ-isomers of pyridylethanamide, 3-pyridylpropanamide, 4-pyridylbutanamide, 5-pyridylpentanamide, pyridylmethanol, 2-pyridylethanol, 3-pyridylpropanol, 4-pyridylbutanol, 5-pyridylpentanol, pyridylmethylamine, 2-pyridylethylamine, 3-pyridylpropylamine, 4-pyridylbutylamine, and 5-pyridylpentylamine.While a field effect accounts for many variations in pK_a as a function of chain length, marked inductive effects are operative in some methyl and ethyl homologs.The pK_a-decreasing influence of an intramolecular H-bond is also apparent in some lower homologs belonging to the α-series.