Potassium Phosphate, Tribasic → Ethyl 2-[6-{1-[(1,1-dimethylethyl)(dimethyl)silyl]-1H-indol-4-yl}-1-(phenylsulfonyl)-1H-indazol-4-yl]-1,3-oxazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 2-[6-chloro-1-(phenylsulfonyl)-1H-indazol-4-yl]-1,3-oxazole-5-carboxylate (1.5 g, 3.47 mmol) in 1,4-dioxane (15 ml) and water (1.5 ml) was added {1-[(1,1-dimethylethyl)(dimethyl)silyl]-1H-indol-4-yl}boronic acid (1.243 g, 4.52 mmol, available from Combi-Blocks Inc.), chloro[2′-(dimethylamino)-2-biphenylyl]palladium-1(1R,4S)-bicyclo[2.2.1]hept-2-yl[(1S,4R)-bicyclo[2.2.1]hept-2-yl]phosphane (0.097 g, 0.174 mmol) and potassium phosphate tribasic (2.212 g, 10.42 mmol). The reaction mixture was heated to 100° C. for 3 h, the solvent removed in vacuo and the residue partitioned between dichloromethane (20 ml) and water (10 ml). Saturated sodium chloride solution (100 ml) was added and the organic phase separated and dried over anhydrous sodium sulphate. The crude product was purified by silica gel chromatography, eluting with a gradient of cyclohexane and ethyl acetate. The desired fractions were concentrated to give the title compound as a white solid (0.846 g), which by LCMS contained some unreacted starting material.

Provenance & Evidence