Next Generation NMR Flow Tube Optimized for Small Volume NMR Reaction Monitoring in Preclinical Drug Discovery

Abstract We developed a 3 mm NMR flow tube that can be inserted into a 5 mm NMR probe converting a high field NMR spectrometer into a reaction monitoring system with a minimum reaction volume of 2 mL. The system uses a standard LC pump to flow the reaction mixture from a reaction vial in an integrated heating block to the center of the magnet for detection before returning the mixture back to the vial. The NMR flow tube has a temperature range of −20 to 120 °C and the NMR instrument can be switched from NMR tubes to the flow tube mode in a few minutes. We report the use of this flow NMR small volume system to monitor the progress of two chemical reactions that resisted study by more common analytical techniques.