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

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