Through regulation of the epigenome, the bromodomain and extra terminal (BET) family of proteins represent important therapeutic targets for the treatment of human disease. Through mimicking the endogenous N-acetyl-lysine group and disrupting the protein-protein interaction between histone tails and the bromodomain, several small molecule pan-BET inhibitors have progressed to oncology clinical trials. This work describes the medicinal chemistry strategy and execution to deliver an orally bioavailable tetrahydroquinoline (THQ) pan-BET candidate. Critical to the success of this endeavor was a potency agnostic analysis of a data set of 1999 THQ BET inhibitors within the GSK collection which enabled identification of appropriate lipophilicity space to deliver compounds with a higher probability of desired oral candidate quality properties. SAR knowledge was leveraged via Free-Wilson analysis within this design space to identify a small group of targets which ultimately delivered I-BET567 (27), a pan-BET candidate inhibitor that demonstrated efficacy in mouse models of oncology and inflammation.

This article describes two routes toward the synthesis of cis or trans C2,3,5,7-tetrasubstituted dihydrobenzofurans as potent and selective bromodomain and extra-terminal BD2 inhibitors, followed by the optimization of the synthesis of the lead molecule GSK973 to support pre-clinical efficacy and safety studies. The use of flow chemistry for a Claisen rearrangement, extensive optimization of the fluorination step, and high-yielding aminocarbonylation were key to generate the required 50 g of material. The identified new route also represents a robust starting point for further optimization.

A large-scale process for the synthesis of SYK inhibitor 1 has been developed and used to deliver multi-kilogram yields of this active pharmaceutical ingredient. Integral to the scalable process is a combined chiral auxiliary and chiral catalyst mediated diastereoselective fluorination. Safe processes for BH3 center dot DMS-mediated reduction of ester and amide functions and azide introduction, and a robust Suzuki-Miyaura coupling of a pyrazyl boronate with chloronapthyridine, are described.

The supply route to GlaxoSmithKline's 5HT(4) receptor agonist 1 centred on the construction of key benzopyran fragment 2. Our attempts to define the final manufacturing route for this component are described through it series of disconnections. The systematic approach undertaken towards the construction of the benzopyran skeleton focused on cyclisation strategies front appropriate precursors and evaluation of the performance of the key steps.