A brief introduction to the GSK Green chemistry reagents and solvents guides followed by a case example utilising the tools that focusses on two routes towards the synthesis of cis or trans C2,3,5,7-tetrasubstitued dihydrobenzofurans as potent and selective BET BD2 inhibitors followed by the optimisation of the synthesis of the lead GSK973 to support pre-clinical efficacy and safety studies. The use of flow chemistry for a Claisen rearrangement, an extensive optimisation of a fluorination step and a high yielding aminocarbonylation were key to generate the required 50 g of material.
