With a useful LC-MS method established, we next explored the effect of changing reaction conditions on the reaction profile using HTE. Given that most reported examples of phenanthridinone 2 syntheses use polar aprotic solvents (typically DMF and DMA) at temperatures between 100-150 °C (Scheme 1), alongside the solvent effects observed by Porée et al., we selected to study the effect of solvent and temperature in further detail. To this end we selected seven separate solvents {DMF, propylene carbonate, acetonitrile, n-butyronitrile, methyl ethyl ketone (MEK), di-n-butyl ether and toluene} that covered a wide range of polarities, as well as a 9:1 n-Bu2O:DMF mixture. Furthermore, propylene carbonate, 27 and MEK were selected primarily as potentially greener and less toxic alternatives. Five temperatures between 80-120 °C (10 °C intervals) were chosen, as were several reaction time-points from 1 to 8 h to provide a temporal visualization of the altering product(s) profile. Reactions were conducted at 130 °C, but significant solvent losses were noted in these experiments leading to unreliable data. We elected to perform the HTE campaign without a catalyst pre-activation step (see Scheme 3B) to avoid variability in the experimental workflow, which facilitated the range of side-products generated to be fully explored.