Cesium carbonate → ethyl 3-[5-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1H-indazol-1-yl]-2,2-dimethylpropanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1H-indazole (D4) (122 mg, 0.344 mmol) in DMF (2 ml) was treated with ethyl 3-bromo-2,2-dimethylpropanoate (D98) (79 mg, 0.378 mmol) and Cs2CO3 (134 mg, 0.413 mmol) and the resulting mixture was stirred at 80° C. overnight. More ethyl 3-bromo-2,2-dimethylpropanoate (D98) (29 mg, 0.4 mmol) and Cs2CO3 (56 mg, 0.5 mmol) were added and the resulting mixture stirred at 80° C. for 6 h then cooled to room temperature and concentrated in vacuo. The residue was dissolved in EtOAc and the organic phase was washed with water then brine, dried and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel [gradient ethyl acetate/cyclohexane] gave ethyl 3-[5-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1H-indazol-1-yl]-2,2-dimethylpropanoate (D100) (92 mg, 55%) and ethyl 3-[5-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-2H-indazol-2-yl]-2,2-dimethylpropanoate (D101) (49 mg, 30%). MS (ES) C25H27ClN4O4 requires 482, found 483 [M+H]+

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