Evolution of a Scale-Up Synthesis to a Potent GluN2B Inhibitor and Its Prodrug

This paper describes the efficient scale-up synthesis of the potent negative allosteric glutamate N2B (GluN2B) inhibitor 1 (BMS-986169), which relies upon a stereospecific SN2 alkylation strategy and a robust process for the preparation of its phosphate prodrug 28 (BMS-986163) from parent 1 using POCl3. A deoxyfluorination reaction employing bis­(2-methoxyethyl)­aminosulfur trifluoride (Deoxo-Fluor) is also used to stereospecifically introduce a fluorine substituent. The optimized routes have been demonstrated to provide APIs suitable for toxicological studies in vivo.