Enamine provided 19 F NMR chemical shifts measured in 1 mM PBS and reported a KF 19 F NMR chemical shift as a standard for every measurement. Occasionally Enamine reports two peaks for a single compound. In these cases, the first peak is taken as a representative. At Novartis the LEF 19 F NMR chemical shifts were recorded in 50 mM deuterated Tris buffer at pH 7.6, containing 100 mM NaCl, 100 µM sodium trimethylsilylpropanesulfonate (DSS), and 2% DMSO-d6. Measurements were performed at 296 K (23 °C) with DSS as indirect referencing for 19 F NMR chemical shift calibration.