1.5 kg of product in 9 hours in a continuous flow Firefly reactor by applying a [2+2] cycloaddition under UV irradiation of very high intensity (3 kW) . Using a similar method, Britton et al. produced 45 g of fluorinated leucine in 2 h . Recently, researchers at AbbVie were able to reach kg•day -1 scale for a C-N coupling reaction in a CSTR using a catalyst with a low absorption coefficient, therefore making it possible to irradiate the reactor efficiently . However, even though these studies show that an effective reactor design significantly improves the performance of photochemical systems by increasing interfacial area and/or light penetration, only a few examples of industrial scale photochemical production are known , due to the absence of effective photochemical reactors with high productivity.