The photoreactions of pyridine and 2-fluoropyridine with aliphatic amines

Abstract

Pyridine undergoes photochemical reaction with diethylamine, triethylamine, and diethyl ether to give 2- and 4-substituted pyridines which reflect attack at the α-CH₂ of the amine and the ether. Irradiation of 2-fluoropyridine with t-butylamine and diethylamine results solely in a nucleophilic displacement reaction and the formation of the 2-alkylaminopyridines but triethylamine and 2-fluoropyridine yield 2-(N,N-diethylamino)pyridine and a compound tentatively identified as 2-(N-ethyl-N-n-propylamino)pyridine. Mechanistic considerations are discussed in terms of pathways previously proposed for arene-amine photoreactions.