1,4-Dioxane → 1,1-Dimethylethyl 4-[4-cyano-1-(phenylsulfonyl)-1H-indazol-6-yl]-1H-indole-1-carboxylate

Participants

Reaction Steps

To a round bottomed flask was charged 6-bromo-1-(phenylsulfonyl)-1H-indazole-4-carbonitrile (10 g, 27.6 mmol), 1,1-dimethylethyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-indole-1-carboxylate (14.21 g, 41.4 mmol) and potassium phosphate tribasic (17.58 g, 83 mmol). The resulting mixture was treated with 1,4-dioxane (120 ml) and water (12 ml) that had previously been purged with nitrogen. The mixture was then treated with 1′-bis(diphenylphosphino)ferrocene palladium dichloride (1.547 g, 2.76 mmol) and heated to reflux, under nitrogen for 2 h. Additional 1′-bis(diphenylphosphino)ferrocene palladium dichloride (1.547 g, 2.76 mmol) was added and the mixture heated at reflux for a further 1 h. The hot reaction mixture was filtered through Celite, washed well with chloroform and the filtrate concentrated in vacuo. The residue was dissolved in DCM/cyclohexane (1:1, 50 ml) and purified by column chromatography on silica (750 g cartridge), eluting with 0-40% ethyl acetate/cyclohexane. The pure fractions were combined and concentrated to give the title compound as a yellow solid (6.16 g).

Provenance & Evidence