To a 20 mL glass microwave tube containing 2-cyclopropyl-5-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (340 mg, 0.673 mmol) was added 2-bromo-4-cyclopropylpyrimidine (154 mg, 0.774 mmol) (CombiPhos Catalysts Inc.), potassium phosphate (428 mg, 2.018 mmol) (Sigma-Aldrich), dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (19.24 mg, 0.040 mmol) (Strem), and Pd2(dba)3 (18.48 mg, 0.020 mmol) (Strem). The tube was purged with argon, the solids were treated with dioxane (6.0 mL) and water (0.600 mL), the tube was sealed, and the contents were heated in an Initiator microwave reactor (Personal Chemistry, Biotage AB, Inc., Upssala, Sweden) at 100° C. for 20 min. The mixture was treated with water and extracted with EtOAc. The organic layer was washed with brine, dried over MgSO4, filtered and concentrated. The crude material was purified by flash chromatography (20-70% EtOAc in Hex) affording 2-cyclopropyl-5-(3-(4-cyclopropylpyrimidin-2-yl)-1-tosyl-1H-indol-5-yl)-1,3,4-oxadiazole (78.6 mg, 0.158 mmol, 23.48%) as an amorphous, rust-coloured solid. MS (ESI, pos. ion) m/z: 498.1 (M+1).
