Substitution of Cyano Group by Hydroxyalkyl Group and of Ring Hydrogen by Alkoxyl Group in UV-Irradiation of 2-Pyridinecarbonitrile in Alcohols
The UV-irradiation of 2-pyridinecarbonitrile(1) in methanol and in ethanol brings about the replacement of the cyano group by the hydroxyalkyl groups and the replacement of the ring hydrogen by the alkoxyl group.Free base-form of 1 in ethanol undergoes exclusively photo-hydroxyethylation, while the pyridinium form of 1 in ethanol undergoes both photo-hydroxyethylation via a singlet excited state and -ethoxylation via a singlet-excited state complex, which is quenched by the electron transfer from the aromatic hydrocarbons to the excited complex.