We describe the development and scale-up of a nickel-catalyzed reductive cross-electrophile coupling reaction between a substituted 2-chloropyridine and ethyl 3-chloropropanoate using manganese dust as the terminal reductant. Several additives were screened for the activation of the manganese reductant in situ, and chlorotriethylsilane (TESCl) was found to provide the optimal conversion. A focused beam reflectance measurement (FBRM) probe was utilized to monitor particle attrition as well as manganese activation during the reaction. Modeling was employed to garner an understanding of mixing requirements that would ensure effective suspension of the manganese during scale-up. The process was successfully demonstrated on a 7 kg scale and afforded 2 in 64% yield.

A modified synthetic route to BMS-978587 was developed featuring a chemoselective nitro reduction and a stereospecific Suzuki coupling as the key bond formation steps. A systematic evaluation of the reaction conditions led to the identification of a robust catalyst/ligand/base combination to reproducibly effect the Suzuki reaction on large scale. The modified route avoided several challenges with the original synthesis and furnished the API in high overall yield and purity without recourse to chromatography.