Sodium Carbonate → Abiraterone Acetate

Beteiligte Stoffe

Reaktionsschritte

Trifluoromethanesulphonic anhydride (235 g) is dropped into a solution of prasterone acetate (250 g) in methylene chloride (5 L), maintaining the temperature between −5° C. and 0° C., and anhydrous sodium carbonate (80 g) is added in portions. The mixture is stirred for 4 h at 0-5° C. Cold water (2.5 L) is added and the organic phase is separated and washed with a 10% sodium chloride aqueous solution. The mixture is treated with decolourising carbon (120 g), and then concentrated under vacuum to obtain an oily residue (about 355 g). The vinyl triflate thus obtained is taken up with tetrahydrofuran (3.0 L), and diethyl(3-pyridyl)borane (100 g), bis(triphenylphosphine)palladium II chloride (3.3 g) and a 2M sodium carbonate aqueous solution (900 mL) are loaded in succession in an inert gas environment. The resulting mixture is refluxed for about 1 h, then cooled to room temperature, and ethyl acetate (2.5 L) and water (2.5 L) are added. The aqueous phase is back-extracted with ethyl acetate (1.4 L), and the combined organic phases are treated with decolourising carbon (about 100 g), and then concentrated under vacuum to obtain crude abiraterone acetate as an oil (304 g; purity about 92%; assay 52%).

Herkunft & Nachweise