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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a suspension of magnesium powder (0.73 g, 30.2 mmol) in anhydrous THF (50 mL) under nitrogen was added dibromoethane (2.13 g, 0.98 mL, 11.3 mmol) in portions over about 30 min. During this period the mixture was heated at about 50° C. until gas evolution was observed. The mixture was stirred for an additional 1 h, placed in an ice bath, and a solution of the product from Step D (3.33 g, 7.55 mmol) in THF (10 mL) was added. After stirring for 1 h at ambient temperature, the mixture was quenched with a saturated aqueous solution of ammonium chloride (100 mL) and extracted with EtOAc (3×100 mL). Evaporation of the extracts gave a crude oil (3.76 g, 95%): LC/MS (+APCI) m/z 441, 443 (M+H−HBr).

Herkunft & Nachweise