Photoreactivity of triazolopyridinones, including the drug trazodone, in aqueous solution

Abstract

Irradiation of triazolo[4,3-a]pyridin-3-ones at 310nm has been investigated in water/acetonitrile (7%). Cis-cisoid-fused cyclobutanes are generally obtained. Cage products are found starting from derivatives bearing (piperazin-1-yl)aryl moiety under dilute conditions (10−3M). Two different routes appear to be involved in the formation of the observed photoproducts. A plausible mechanistic explanation is reported.