title: A practical flow reactor for continuous organic photochemistry.
abstract: [reaction: see text] Compact flow reactors have been constructed and optimized to perform continuous organic photochemistry on a large scale. The reactors were constructed from commercially available or customized immersion well equipment combined with UV-transparent, solvent-resistant fluoropolymer (FEP) tubing. The reactors were assessed using the [2 + 2] photocycloaddition of malemide 1 and 1-hexyne forming the cyclobutene product 2 and the intramolecular [5 + 2] photocycloaddition of 3,4-dimethyl-1-pent-4-enylpyrrole-2,5-dione 3 to form the bicyclic azepine 4. The reactors were shown to be capable of producing >500 g of 2 and 175 g of 4 in a continuous 24 h processing period. Due to the facile control of irradiation time, the continuous flow reactor was also shown to be superior to a batch reactor for performing a problematic photochemical reaction on a larger scale.
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
authors.forename: Benjamin D A
authors.initials: BD
authors.lastname: Hook
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dohle
authors.forename: Paul R
authors.initials: PR
authors.lastname: Hirst
authors.forename: Mark
authors.initials: M
authors.lastname: Pickworth
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Berry
authors.forename: Kevin I
authors.initials: KI
authors.lastname: Booker-Milburn