Abstract
The photolysis of diphenyl sulfone in neat pyridine or pyridine diluted with the organic solvent, with a high-pressure mercury arc lamp, was studied. The presence of acetone in the reaction system remarkably promoted photochemical conversion of the sulfone. The isomer distribution ratios (β > α > γ) of phenylpyridines produced during the reaction were clearly different from those (α > β > γ) so far reported for a free-radical phenylation of pyridine. Benzenesulfinic acid produced in the reaction was separated from the product mixture and identified as its S-benzylthiuronium derivative.