(26a) Assessing the Relative Merits of Pharma Reactions in Flask Vs Flow

Blackmond, D. G., The Scripps Research Institute

The future for the combination of microflow reactors and organic synthetic chemistry for phamaceutical applications is bright, and many novel and creative applications for these reactor systems will find their place in academic and industrial laboratories. However, the decision of whether to run a complex liquid or multiphase organic reaction in a flask or in a microflow reactor must be made on a case-by-case basis. This lecture advocates placing highest priority on a holistic picture including careful study of the process thermochemistry and relevant transport phenomena as well as the reaction chemistry and production requirements in order to make the decision wisely. Discussion points are offered specifically for the case of one-phase, homogeneous catalytic reactions. Mixing considerations are addressed as well as the role of heat transfer, introducing simple calculations that help to assess these issues both at the laboratory and at the plant scale.  We argue the case for applying reaction progress monitoring in batch as the most efficient and information-rich means of obtaining a comprehensive kinetic analysis that may then be used to help choose the optimal reactor type.