Shedding Blue Light on the Undergraduate Laboratory: An Easy-to-Assemble LED Photoreactor for Aromatization of a 1,4-Dihydropyridine

A photochemical reactor was tested in an undergraduate teaching laboratory through the environmentally friendly aromatization of a 1,4-dihydropyridine, successfully using air as an oxidant, organic dye fluorescein as a photosensitizer, and sodium carbonate as a base. This experiment allowed students to be taught key concepts of photochemistry, organic photoredox catalysis, and green chemistry for the first time. Herein, we describe the making of the simple, yet robust, high-intensity blue LED photoreactor. The durable device was constructed with materials acquired at a hardware store and electronics shop.