1,1-Dibromoethane → 1-Bromo-3-[7-bromo-1-[2-(tert-butyl-dimethyl-silanyloxy)-propyl]-1H-indazol-6-yloxy]-propan-2-ol

Participants

Reaction Conditions

Reaction Steps

Dibromoethane (1.09 mL, 12.6 mmol) was added dropwise to a suspension of magnesium powder (0.81 g, 33.5 mmol) in anhydrous THF (150 mL) under nitrogen. During this period the mixture was heated at about 50° C. until gas evolution was observed and then allowed to cool to 40° C. Additional dibromoethane (0.05 mL) was added and the mixture was heated at reflux for 20 min and placed in an ice bath. To the cooled mixture was added a solution of the product from Step D (3.70 g, 8.38 mmol) in THF (50 mL). After stirring for 20 min at ambient temperature, the reaction was quenched with a saturated aqueous solution of ammonium chloride (200 mL) and the mixture was extracted with EtOAc (2×150 mL). Evaporation of the extracts gave a crude oil (3.78 g, 86%): LC/MS (+APCI) m/z 521, 523, 525 (M+H).

Provenance & Evidence