Ethyl bromoacetate → [1-((S)-2-Benzyloxycarbonylamino-propyl)-7-bromo-1H-indazol-6-yloxy]-acetic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

To a mixture of the compound from Step A (0.90 g, 2.23 mmol), potassium carbonate (0.40 g, 2.90 mmol) in acetone (80 mL) was added ethyl bromoacetate (0.484 g, 0.32 mL, 2.90 mmol) with stirring. The mixture was heated at reflux temperature for 3 h and evaporated to dryness. The residue was mixed with water (100 mL) and extracted with EtOAc (3×60 mL). The combined extracts were dried over magnesium sulfate, filtered and evaporated to dryness. Chromatography on silica eluting with a gradient of 10% to 30% EtOAc/hexane gave a solid (0.92 g, 84%): mp 89-90° C.; LCMS (+APCI) 490, 492 (M+H).

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