Application of Flow Photochemical Bromination in the Synthesis of a 5-Bromomethylpyrimidine Precursor of Rosuvastatin: Improvement of Productivity and Product Purity

In this report we present a flow photochemical bromination of a 5-methyl-substituted pyrimidine precursor of rosuvastatin. The study demonstrated that the reaction productivity can be increased markedly with a flow-mode approach compared to a batch-mode synthesis. Indeed, reaction times can be significantly shortened from a range of hours to a range of minutes. Moreover, in addition to process intensification, the study demonstrated that significantly lower overall levels of side products are obtained when photochemical bromination is conducted in a flow mode.