Yield:130840-21-0 53%

Reaction Conditions:

with caesium carbonate in acetonitrile at 100; for 3.5 h;

Steps:

46.A

A. 4-[(2-Bromoethyl)oxy]phenyl methyl sulfone20 To a solution of 4-(methylsulfonyl)phenol (0.30 g, 1.74 mmol) in MeCN (5 mL) was added Cs₂C0₃ (0.71 g, 2.18 mmol) and 1,2-dibromoethane (1.64 g, 8.71 mmol). The resulting mixture was heated in a sealed tube at 100°C. After 1.5 h Cs₂C0₃ (0.4 g, 1.21 mmol) was added and heated at 100°C for another 2 h. Upon cooling, the mixture was partitioned between EtOAc and 1N NaOH. The organic phase was washed with sat'd brine, dried (Na2SC>4) and concentrated in vacuo. The residue was purified by flash chromatography (0-70% 5 EtOAc-hexanes gradient) to afford the title compound as a white solid (0.255 g, 53% yield): MS (ES) m/z 279 and 281 (M+1 Br isotopes).

References:

WO2008/42571,2008,A2 Location in patent:Page/Page column 98-99