5-(5-chloropyridazin-3-yl)-1-methyl-1H-indazole (75.0 mg, 0.307 mmol), bis(pinacolato)diboron (101.2 mg, 0.398 mmol), [1,1′Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex with dichloromethane (37.5 mg, 0.046 mmol), and potassium acetate (90.2 mg, 0.920 mmol) were taken in a microwave vial, and the vial was vacuum pumped and flushed with argon three times. To this mixture was added degassed DMF (3 mL). The reaction mixture was heated at 110° C. for 2 h then cooled. To the cooled reaction mixture was added (S)-ethyl 2-(2-bromo-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate (180.0 mg, 0.368 mmol), tetrakis(triphenylphosphine)palladium(0) (53.1 mg, 0.046 mmol), K2CO3 (127.1 mg, 0.920 mmol) and degassed water (0.5 mL). The reaction mixture was heated to 110° C. for 2 h, cooled, filtered through Celite (ethyl acetate eluent), and concentrated. Purification by flash column chromatography on silica gel (hexanes/ethyl acetate eluent) provided the product. LCMS-ESI+ calc'd for C34H33ClN5O3S (M+H+): 626.2; Found: 625.5 (M+H+).
