Para Tolylation of Pyridine by Photolysis of Di- p -Tolyl Sulfone and Related Compounds

Abstract Di-p-tolyl sulfone, sulfoxide and sulfide, p-toluoyl peroxide, and p-iodotoluene were respectively photolyzed in pyridine with a mercury arc lamp. It was found that all the compounds decompose photochemically to yield the isomeric p-tolylpyridines (α,β , and γ). The isomer distribution ratios (β>α>γ) obtained with the sulfone differ from those (α>β>γ) with the other compounds. The presence of acetone in the reaction system remarkably promoted the photochemical conversion of both the sulfone and sulfoxide.